{"investigation":{"slug":"zcash-orchard-pool-counterfeiting-bug","entity_name":"Zcash Orchard Pool Counterfeiting Bug","trust_score":40,"severity_base":null,"score_modifier":0,"confidence":0.87,"status":"published","content_type":"investigation","summary":"On May 29, 2026, security engineer Taylor Hornby, working for Shielded Labs and using Anthropic's Claude Opus 4.8 model, found a critical soundness flaw in the zero-knowledge proof circuit of Zcash's Orchard shielded pool. The flaw had been present since the pool launched in May 2022 and could have allowed unlimited, undetectable counterfeit ZEC to be created inside the pool. Zcash developers disabled Orchard with an emergency soft fork on June 2 and deployed a corrected circuit in the NU6.2 hard fork on June 3. No exploitation has been found, but because Orchard hides transaction details, it cannot be proven cryptographically that the flaw was never used. After public disclosure on June 5, 2026, ZEC fell about 38% in 24 hours and about 50% over 48 hours.","sections":[{"content":"The flaw was a soundness bug in the Orchard zero-knowledge proof circuit, the component that governs Zcash's most advanced shielded pool, introduced with the NU5 network upgrade. It sat in two lines of the halo2_gadgets crate, in the variable-base scalar multiplication gadget (incomplete.rs, lines 309-310, according to BlockSec). The code used assign_advice() to write the base point coordinates without adding an equality constraint that tied them to the externally supplied value. The correct call, copy_advice(), enforces that the base point used internally is bound to the protocol-specified input: the diversified base point g_d derived from each address's diversifier. Because the elliptic-curve multiplication check was under-constrained, a malicious prover could substitute an arbitrary base point across all loop iterations while staying internally consistent, and the check would still pass. This broke the scalar multiplication relation that enforces pk_d = [ivk] g_d and the uniqueness of nullifiers derived from note keys. Different nullifier keys (nk) produce different nullifiers for the same note, so an attacker could forge nullifiers, double-spend and mint coins without limit inside the Orchard pool. The zero-knowledge proofs would hide the fraudulent inputs, so counterfeit ZEC would look identical to legitimate coins on the public ledger. Zcash's cross-pool turnstile, which enforces balance rules across all value pools, meant the flaw could not inflate the visible total ZEC supply: counterfeit notes could only be created and circulate inside Orchard. Affected software included all halo2_gadgets versions before v0.5.0, all orchard crate versions before v0.14.0, zcashd v5.0.0 through v6.12.3, and all zebrad versions below v4.5.1. Sapling and transparent transactions were not affected.","heading":"Vulnerability description","sources":[{"url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/","name":"Zcash Foundation: Zebra 4.5.3 and 5.0.0 Emergency Soft Fork and NU6.2 Activation","type":"official","credibility":1},{"url":"https://blocksec.com/blog/web3-security-zcash-orchard-soundness-bug-analysis","name":"BlockSec: Zcash Orchard Soundness Bug Analysis","type":"research","credibility":2},{"url":"https://shieldedlabs.net/the-orchard-counterfeiting-vulnerability/","name":"Shielded Labs: The Orchard Counterfeiting Vulnerability","type":"official","credibility":1},{"url":"https://forum.zcashcommunity.com/t/the-orchard-counterfeiting-vulnerability-and-next-steps/56015","name":"Zcash Community Forum: The Orchard Counterfeiting Vulnerability and Next Steps","type":"official","credibility":1},{"url":"https://www.theblock.co/post/403698/zcash-vulnerability-zec-drops","name":"The Block: Security researcher finds Zcash vulnerability allowing 'unlimited' counterfeit minting","type":"news_article","credibility":2},{"url":"https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability","name":"Decrypt: ZEC Crashes 38% as Zcash Discloses 'Critical Counterfeiting Vulnerability'","type":"news_article","credibility":2},{"url":"https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years","name":"CoinDesk: Zcash plummets 38% as Shielded Labs reveals a major bug that went undetected for four years","type":"news_article","credibility":1},{"url":"https://cointelegraph.com/learn/why-zec-fell-after-zcash-orchard-bug-fix","name":"CoinTelegraph: Why ZEC fell 40% even after Zcash patched a shielded pool bug","type":"news_article","credibility":2},{"url":"https://unchainedcrypto.com/ai-assisted-audit-uncovers-critical-zcash-orchard-vulnerability-that-could-have-minted-unlimited-counterfeit-zec/","name":"Unchained Crypto: AI-Assisted Audit Uncovers Critical Zcash Orchard Vulnerability","type":"news_article","credibility":2}],"severity":"critical"},{"content":"Taylor Hornby, an independent security engineer whom Shielded Labs engaged in April 2026 for a targeted protocol audit aimed at finding vulnerabilities before malicious actors could, discovered the flaw on May 29, 2026. He used a custom AI-assisted auditing harness and targeted prompts built around Anthropic's Claude Opus 4.8 model, which had been publicly released on May 28, 2026, the day before. Hornby wrote a complete proof-of-concept exploit that generated unlimited, undetectable counterfeit ZEC in a local (regtest) environment. On the evening of May 29 he disclosed the vulnerability to a small group of cryptographers at the Zcash Open Development Lab (ZODL). ZODL engineers Daira-Emma Hopwood, Kris Nuttycombe and Jack Grigg (Str4d) confirmed the issue and began coordinating a fix within hours. ZODL executive Josh Swihart was alerted via Signal on May 30 and joined a secure video call to coordinate the emergency response. Shielded Labs said the bug had 'evaded years of scrutiny by experienced cryptographers', having survived several rounds of expert human auditing since Orchard's launch in May 2022. The case has been widely cited as an early example of AI-assisted discovery of a vulnerability in a production cryptographic system.","heading":"Discovery and AI-assisted audit","sources":[{"url":"https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years","name":"CoinDesk: Zcash plummets 38% as Shielded Labs reveals a major bug that went undetected for four years","type":"news_article","credibility":1},{"url":"https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability","name":"Decrypt: ZEC Crashes 38% as Zcash Discloses 'Critical Counterfeiting Vulnerability'","type":"news_article","credibility":2},{"url":"https://www.cryptotimes.io/2026/06/08/inside-zcashs-50-hour-race-to-save-orchard-from-exploit/","name":"Crypto Times: Inside Zcash's 50-Hour Race to Save Orchard From Exploit","type":"news_article","credibility":2},{"url":"https://www.blockhead.co/2026/06/05/zcash-founder-discloses-critical-orchard-forgery-flaw-fixed-by-emergency-hard-fork/","name":"Blockhead: Claude AI Finds Critical Vulnerability in Zcash","type":"news_article","credibility":2},{"url":"https://unchainedcrypto.com/ai-assisted-audit-uncovers-critical-zcash-orchard-vulnerability-that-could-have-minted-unlimited-counterfeit-zec/","name":"Unchained Crypto: AI-Assisted Audit Uncovers Critical Zcash Orchard Vulnerability","type":"news_article","credibility":2},{"url":"https://beincrypto.com/zcash-zec-orchard-counterfeiting-bug/","name":"BeInCrypto: An Opus 4.8 Audit Uncovered Zcash's Bug","type":"news_article","credibility":2},{"url":"https://www.theblock.co/post/403698/zcash-vulnerability-zec-drops","name":"The Block: Security researcher finds Zcash vulnerability allowing 'unlimited' counterfeit minting","type":"news_article","credibility":2},{"url":"https://forum.zcashcommunity.com/t/the-orchard-counterfeiting-vulnerability-and-next-steps/56015","name":"Zcash Community Forum: The Orchard Counterfeiting Vulnerability and Next Steps","type":"official","credibility":1},{"url":"https://shieldedlabs.net/the-orchard-counterfeiting-vulnerability/","name":"Shielded Labs: The Orchard Counterfeiting Vulnerability","type":"official","credibility":1}],"severity":"high"},{"content":"ZODL coordinated a two-phase emergency response within about 50 hours of the internal disclosure. Private coordination with miners, exchanges and node operators began on May 31. Phase one was a soft fork, shipped in Zebra 4.5.3, that disabled all Orchard-containing transactions and blocks to prevent exploitation while the circuit fix was completed. It activated at mainnet block height 3,363,426. Most accounts put activation at about 02:00 UTC on June 2, 2026, but one CryptoTimes-based account gives 22:30 EDT on June 1. The team deliberately did not ship a direct circuit patch in this phase, because doing so would have revealed the flaw before miners and node operators could upgrade. The initial two-hour activation window proved too short and was extended after coordination with the mining pools ViaBTC and Foundry. ZODL also released zcashd v6.12.5. Phase two was the NU6.2 hard fork, which activated at mainnet block height 3,364,600 at 00:05 EDT on June 3, 2026, via Zebra 5.0.0 (testnet activation at block 4,052,000). NU6.2 re-enabled Orchard with a corrected circuit: the fix adds a copy_advice() call in the first loop iteration of the scalar multiplication component, anchoring the base point to the external input and carrying it through later iterations. NU6.2 also added a consensus rule rejecting Orchard bundles with non-canonical proof sizes. Other patched releases were halo2_gadgets v0.5.0 and orchard v0.14.0. The switchover caused some chain instability. Community member Kenbak documented a 25-block fork spanning heights 3,363,431 to 3,363,455, with 37 orphaned blocks from nodes still running older software. It resolved in favor of the patched chain; accounts differ on whether it happened during the June 2 soft fork or the June 3 NU6.2 switchover. Cake Wallet temporarily suspended all ZEC functionality, and some exchanges paused ZEC deposits and withdrawals during the soft fork window. ZODL said no known exploitation had occurred before the intervention and that user funds were secure. Sapling and transparent transactions were unaffected throughout.","heading":"Emergency response: soft fork and NU6.2 hard fork","sources":[{"url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/","name":"Zcash Foundation: Zebra 4.5.3 and 5.0.0 Emergency Soft Fork and NU6.2 Activation","type":"official","credibility":1},{"url":"https://www.cryptotimes.io/2026/06/02/zcash-executes-emergency-fork-after-critical-orchard-vulnerability-discovery/","name":"Crypto Times: Zcash Executes Emergency Fork After Critical Orchard Vulnerability Discovery","type":"news_article","credibility":2},{"url":"https://www.cryptotimes.io/2026/06/03/zcash-activates-nu6-2-hard-fork-following-double-spend-risk-discovery/","name":"Crypto Times: Zcash Activates NU6.2 Hard Fork Following Double-Spend Risk Discovery","type":"news_article","credibility":2},{"url":"https://www.cryptotimes.io/2026/06/08/inside-zcashs-50-hour-race-to-save-orchard-from-exploit/","name":"Crypto Times: Inside Zcash's 50-Hour Race to Save Orchard From Exploit","type":"news_article","credibility":2},{"url":"https://forum.zcashcommunity.com/t/the-orchard-counterfeiting-vulnerability-and-next-steps/56015","name":"Zcash Community Forum: The Orchard Counterfeiting Vulnerability and Next Steps","type":"official","credibility":1},{"url":"https://cryptobriefing.com/zcash-orchard-bug-emergency-upgrade/","name":"CryptoBriefing: Zcash fixes critical Orchard bug after emergency network upgrade","type":"news_article","credibility":2},{"url":"https://crypto-economy.com/zcash-pushes-emergency-update-to-patch-orchard-bug-network-briefly-unstable/","name":"Crypto Economy: Zcash Pushes Emergency Update to Patch Orchard Bug, Network Briefly Unstable","type":"news_article","credibility":2},{"url":"https://www.kucoin.com/news/flash/zcash-deploys-emergency-update-to-fix-orchard-bug-network-experiences-brief-instability","name":"KuCoin: Zcash Deploys Emergency Update to Fix Orchard Bug","type":"news_article","credibility":2},{"url":"https://cointelegraph.com/learn/why-zec-fell-after-zcash-orchard-bug-fix","name":"CoinTelegraph: Why ZEC fell 40% even after Zcash patched a shielded pool bug","type":"news_article","credibility":2},{"url":"https://blocksec.com/blog/web3-security-zcash-orchard-soundness-bug-analysis","name":"BlockSec: Zcash Orchard Soundness Bug Analysis","type":"research","credibility":2}],"severity":"high"},{"content":"No confirmed exploitation has been found on mainnet. The Zcash Foundation said the flaw was 'caught before any known exploitation occurred', with 'no evidence of unauthorized value creation', and the turnstile accounting confirmed that total ZEC supply stayed intact. However, Shielded Labs and the Zcash Foundation both acknowledged a basic limit. As Shielded Labs put it, 'due to the privacy properties of Orchard and the nature of the bug, there is no definitive way to determine using only cryptography whether such exploitation occurred' during the roughly four years from May 2022 to June 2026. If anyone had found the flaw independently, any exploitation would have left no traceable on-chain signature. Zooko Wilcox said the flaw 'could have been exploited to undetectably create an unlimited amount of counterfeit ZEC within Orchard' and that there is 'no way to cryptographically prove whether the vulnerability was exploited before it was remediated.' Shielded Labs said exploitation was 'unlikely' and that it was 'not overly concerned', reasoning that the bug had evaded years of expert scrutiny and was found only through targeted AI-assisted review. Grayscale Chief Legal Officer Craig Salm argued that pre-patch exploitation was improbable: an attacker would have needed exceptional code-review skills and would have had every economic reason to drain the pool during bull-market conditions rather than hold counterfeit coins quietly. These assessments are probabilistic, not cryptographic. When the emergency fork happened, about 30% of circulating ZEC (roughly 5 million coins) was held in shielded addresses.","heading":"Exploitation status and supply integrity","sources":[{"url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/","name":"Zcash Foundation: Zebra 4.5.3 and 5.0.0 Emergency Soft Fork and NU6.2 Activation","type":"official","credibility":1},{"url":"https://shieldedlabs.net/the-orchard-counterfeiting-vulnerability/","name":"Shielded Labs: The Orchard Counterfeiting Vulnerability","type":"official","credibility":1},{"url":"https://forum.zcashcommunity.com/t/the-orchard-counterfeiting-vulnerability-and-next-steps/56015","name":"Zcash Community Forum: The Orchard Counterfeiting Vulnerability and Next Steps","type":"official","credibility":1},{"url":"https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability","name":"Decrypt: ZEC Crashes 38% as Zcash Discloses 'Critical Counterfeiting Vulnerability'","type":"news_article","credibility":2},{"url":"https://www.blockhead.co/2026/06/05/zcash-founder-discloses-critical-orchard-forgery-flaw-fixed-by-emergency-hard-fork/","name":"Blockhead: Claude AI Finds Critical Vulnerability in Zcash","type":"news_article","credibility":2},{"url":"https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years","name":"CoinDesk: Zcash plummets 38% as Shielded Labs reveals a major bug that went undetected for four years","type":"news_article","credibility":1},{"url":"https://www.bloomberg.com/news/articles/2026-06-14/crypto-token-s-50-wipeout-shows-magnitude-of-ai-hacking-threat","name":"Bloomberg: Crypto Token's 50% Wipeout Shows Scale of AI-Hacking Threat","type":"news_article","credibility":1},{"url":"https://www.bitmex.com/blog/zec-crash-2026","name":"BitMEX Blog: Why Zcash Crashed Nearly 50% in 48 Hours","type":"news_article","credibility":2}],"severity":"critical"},{"content":"ZEC had risen sharply before the disclosure: about 91% between May 1 and a late-May peak of $670, and up from a cycle low of $35 in August 2025. After the NU6.2 hard fork, ZEC rallied from about $544 and stayed above $600, and a post-patch rise of more than 10% was reported as Orchard operations resumed. Reports differ on the June 4 high: about $635 according to CoinDesk and Decrypt, about $624 according to BitMEX and CoinTelegraph. After Shielded Labs' public disclosure on June 5, ZEC fell to an intraday low of about $309. Decrypt, CoinDesk and CryptoBriefing reported a 24-hour decline of about 37.8-38%, while BitMEX, KuCoin and Crowdfund Insider described a fall of about 50-51% from peak to trough over 48 hours. Accounts of the later price also differ: the price partially recovered to about $330-$442 by end of day by one account, settled at about $330 by another, and a third cites CoinDesk reporting a 38% decline to $442.60 within the first 24 hours. The market-cap loss exceeded $3 billion, and trading volume fell about 57% as liquidity dried up. Some exchanges temporarily suspended ZEC deposits and withdrawals during the soft fork window. One large investor reportedly lost more than half the value of a ZEC position worth about $174 million. Holders pulled about 1% of the Orchard pool's holdings, a withdrawal Crypto Briefing put at about 202,000 ZEC. After the Ironwood upgrade proposal on June 8, ZEC rebounded about 45% from its post-disclosure low near $300 but remained down about 22% for the week.","heading":"Market impact","sources":[{"url":"https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years","name":"CoinDesk: Zcash plummets 38% as Shielded Labs reveals a major bug that went undetected for four years","type":"news_article","credibility":1},{"url":"https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability","name":"Decrypt: ZEC Crashes 38% as Zcash Discloses 'Critical Counterfeiting Vulnerability'","type":"news_article","credibility":2},{"url":"https://cryptobriefing.com/zcash-plunges-counterfeiting-vulnerability/","name":"CryptoBriefing: Zcash plunges 38% after critical counterfeiting vulnerability disclosure","type":"news_article","credibility":2},{"url":"https://cryptobriefing.com/zcash-orchard-pool-withdrawal-counterfeiting-bug/","name":"CryptoBriefing: Zcash's Orchard pool sees 1% withdrawal as counterfeiting bug shakes investor confidence","type":"news_article","credibility":2},{"url":"https://www.bitmex.com/blog/zec-crash-2026","name":"BitMEX Blog: Why Zcash Crashed Nearly 50% in 48 Hours","type":"news_article","credibility":2},{"url":"https://www.kucoin.com/blog/ZEC-Price-Declines-by-50-percent","name":"KuCoin: ZEC Price Declines by 50% due to Concerns over Zcash's Orchard Pool Bug","type":"news_article","credibility":2},{"url":"https://www.crowdfundinsider.com/2026/06/283931-privacy-focused-zcash-zec-plunges-over-50-as-crypto-investor-arthur-hayes-exits-position-over-unverifiable-counterfeiting-risk/","name":"Crowdfund Insider: Privacy Focused Zcash Plunges Over 50% As Crypto Investor Arthur Hayes Exits","type":"news_article","credibility":2},{"url":"https://www.theblock.co/post/403698/zcash-vulnerability-zec-drops","name":"The Block: Security researcher finds Zcash vulnerability allowing 'unlimited' counterfeit minting; ZEC drops 31%","type":"news_article","credibility":2},{"url":"https://cointelegraph.com/learn/why-zec-fell-after-zcash-orchard-bug-fix","name":"CoinTelegraph: Why ZEC fell 40% even after Zcash patched a shielded pool bug","type":"news_article","credibility":2},{"url":"https://coinpaper.com/17461/zcash-price-rallied-over-10-as-orchard-bug-fix-restored-network/","name":"CoinPaper: Zcash Price Rallied Over 10% as Orchard Bug Fix Restored Network","type":"news_article","credibility":2},{"url":"https://www.coindesk.com/markets/2026/06/05/arthur-hayes-dumps-zcash-holdings-after-orchard-pool-vulnerability-revealed","name":"CoinDesk: Arthur Hayes dumps Zcash holdings after Orchard Pool vulnerability revealed","type":"news_article","credibility":1},{"url":"https://www.coindesk.com/markets/2026/06/08/zcash-bounces-45-as-developers-propose-new-ironwood-upgrade","name":"CoinDesk: Zcash bounces 45% as developers propose new Ironwood upgrade","type":"news_article","credibility":1}],"severity":"high"},{"content":"Arthur Hayes, the BitMEX figure also described as chief investment officer of Maelstrom Fund, publicly exited his entire Zcash position after the disclosure; the pages variously call him BitMEX's former CEO and its co-founder. The pages describe the holding differently: as Hayes's own position, as the second-largest position in his Holy Trinity family fund (bought at a cost basis well below the $624 peak), or as 'BitMEX's entire Zcash position'. Hayes said: 'I read about the exploit yesterday, and didn't appreciate how it violated my narrative mental map.' He said the probability of unauthorized minting was 'extremely low' or 'extremely unlikely' but that it 'cannot be proven cryptographically impossible', and that Zcash's privacy thesis 'demands perfection'. He said he might buy ZEC again at lower prices if his concerns proved wrong. Grayscale CLO Craig Salm offered a counterpoint, arguing that exploitation was improbable though not ruled out. Commentator Udi Wertheimer noted that privacy coins enable 'a unique class of bugs' whose exploitation may never be detected. Ripple CTO David Schwartz said publicly that Zcash appeared safe, while acknowledging that the counterfeiting scenario could not be conclusively disproven.","heading":"Investor and commentator reactions","sources":[{"url":"https://www.coindesk.com/markets/2026/06/05/arthur-hayes-dumps-zcash-holdings-after-orchard-pool-vulnerability-revealed","name":"CoinDesk: Arthur Hayes dumps Zcash holdings after Orchard Pool vulnerability revealed","type":"news_article","credibility":1},{"url":"https://cryptonews.com/news/arthur-hayes-dumps-zcash-orchard-pool-bug/","name":"CryptoNews: Arthur Hayes Just Dumped His Entire Zcash Position","type":"news_article","credibility":2},{"url":"https://finance.yahoo.com/markets/crypto/articles/arthur-hayes-just-dumped-entire-092210665.html","name":"Yahoo Finance: Arthur Hayes Just Dumped His Entire Zcash Position","type":"news_article","credibility":2},{"url":"https://coinlaw.io/arthur-hayes-sells-zec-after-zcash-bug-reveal/","name":"CoinLaw: Arthur Hayes Sells All ZEC After Shocking Zcash Bug Reveal","type":"news_article","credibility":2},{"url":"https://www.bitmex.com/blog/zec-crash-2026","name":"BitMEX Blog: Why Zcash Crashed Nearly 50% in 48 Hours","type":"news_article","credibility":2},{"url":"https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability","name":"Decrypt: ZEC Crashes 38% as Zcash Discloses 'Critical Counterfeiting Vulnerability'","type":"news_article","credibility":2},{"url":"https://cryptonews.com/news/david-schwartz-ripple-zcash-orchard-vulnerability/","name":"CryptoNews: Ripple CTO Says Zcash is Safe: But Fake ZEC Bug Not Disproven","type":"news_article","credibility":2}],"severity":"medium"},{"content":"The response followed a fix-first, disclose-later sequence. Hornby reported the flaw to ZODL engineers on the evening of May 29. For about three days, exchanges, miners and node operators were coordinated privately before the June 2 soft fork. Public disclosure came on June 5, two days after NU6.2 had put a permanent fix in place. This sequencing is consistent with responsible disclosure norms and shortened the window in which anyone else who knew of the flaw could have used it. The emergency hard fork nonetheless drew governance scrutiny: some community members questioned the speed and coordination process used to push through a consensus change. The incident was the second security-driven emergency protocol upgrade since Zcash launched in 2016. Shielded Labs' official disclosure was written by Jason McGee; the pages give its date as June 5, while one source listing gives June 4, and the post was updated on June 15, 2026, according to the article's metadata. A detailed post-mortem of the 50-hour response was published on June 8. It covered the people involved, the technical decisions and plans for the new shielded pool.","heading":"Governance and disclosure process","sources":[{"url":"https://forum.zcashcommunity.com/t/the-orchard-counterfeiting-vulnerability-and-next-steps/56015","name":"Zcash Community Forum: The Orchard Counterfeiting Vulnerability and Next Steps","type":"official","credibility":1},{"url":"https://cryptobriefing.com/zcash-governance-concerns-emergency-hard-fork/","name":"CryptoBriefing: Zcash faces governance concerns after emergency hard fork over critical vulnerability","type":"news_article","credibility":2},{"url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/","name":"Zcash Foundation: Zebra 4.5.3 and 5.0.0 Emergency Soft Fork and NU6.2 Activation","type":"official","credibility":1},{"url":"https://www.cryptotimes.io/2026/06/08/inside-zcashs-50-hour-race-to-save-orchard-from-exploit/","name":"Crypto Times: Inside Zcash's 50-Hour Race to Save Orchard From Exploit","type":"news_article","credibility":2},{"url":"https://shieldedlabs.net/the-orchard-counterfeiting-vulnerability/","name":"Shielded Labs: The Orchard Counterfeiting Vulnerability","type":"official","credibility":1}],"severity":"medium"},{"content":"At the time of the incident, Zcash development was organized under ZODL, with Shielded Labs leading the engagement of outside security researchers. The main remediation engineers were Daira-Emma Hopwood (head of protocol R&D at ZODL), Kris Nuttycombe, Jack Grigg (Str4d) and Arya Solhi (Zcash Foundation), with Josh Swihart coordinating operations. On June 5, Shielded Labs proposed a network upgrade to deploy a new shielded pool with turnstile accounting for all existing Orchard coins. Developers put forward the proposal, called Ironwood, on June 8, targeting late July 2026. Ironwood creates a new shielded pool using the corrected circuit, blocks new deposits into the original Orchard pool and allows only outbound migration. Funds leaving Orchard must pass through a turnstile, Zcash's on-chain accounting that tracks each pool's cumulative inflows and outflows and rejects any transaction trying to move out more ZEC than legitimately went in. If all legitimate funds migrate without rejection and the old pool is emptied, that would be strong evidence the flaw was never exploited. The proposal would let supply integrity be verified independently from then on. On June 15, Zcash founder Zooko Wilcox explained how the turnstiles would act as a live supply audit during migration. The upgrade is also meant to be backed by formal circuit verification, independent audits and continued AI-assisted review, though developers acknowledged that building and coordinating it could push it past the target date. Shielded Labs also announced a formal verification project for the Orchard circuit and successor components, and plans to hire a Head of Security and a dedicated Cryptographer; ZODL said it would expand its security partnerships. In community forum discussion, member conradoplg pointed to the Sprout pool, which was deprecated without mandatory migration, as a precedent against forcing funds out. Other members asked whether any compensation mechanism would exist if counterfeiting had in fact occurred.","heading":"Remediation plans: Ironwood, formal verification and security hires","sources":[{"url":"https://thedefiant.io/news/blockchains/shielded-labs-proposes-new-zcash-upgrade-to-prove-zec-supply-after-orchard-bug","name":"The Defiant: Shielded Labs Proposes New Zcash Upgrade to Prove ZEC Supply After Orchard Bug","type":"news_article","credibility":2},{"url":"https://www.coindesk.com/markets/2026/06/08/zcash-bounces-45-as-developers-propose-new-ironwood-upgrade","name":"CoinDesk: Zcash bounces 45% as developers propose new Ironwood upgrade","type":"news_article","credibility":1},{"url":"https://www.cryptotimes.io/2026/06/15/how-zcashs-ironwood-turnstiles-will-trap-counterfeit-coins/","name":"CryptoTimes: Zcash Orchard Vulnerability: Zooko Explains Why Ironwood Matters","type":"news_article","credibility":2},{"url":"https://cryptonews.com/news/zcash-ironwood-upgrade-orchard-pool-flaw-july/","name":"CryptoNews: Zcash Ironwood Upgrade Finalizes to Patch Orchard Pool Flaw, Targets July","type":"news_article","credibility":2},{"url":"https://www.kucoin.com/blog/en-zcash-to-launch-ironwood-upgrade-at-end-of-july-2026-enhanced-privacy-and-transparency","name":"KuCoin: Zcash to Launch Ironwood Upgrade at End of July 2026","type":"news_article","credibility":2},{"url":"https://www.cryptotimes.io/2026/06/08/inside-zcashs-50-hour-race-to-save-orchard-from-exploit/","name":"Crypto Times: Inside Zcash's 50-Hour Race to Save Orchard From Exploit","type":"news_article","credibility":2},{"url":"https://forum.zcashcommunity.com/t/the-orchard-counterfeiting-vulnerability-and-next-steps/56015","name":"Zcash Community Forum: The Orchard Counterfeiting Vulnerability and Next Steps","type":"official","credibility":1},{"url":"https://cryptobriefing.com/zcash-orchard-bug-emergency-upgrade/","name":"CryptoBriefing: Zcash fixes critical Orchard bug after emergency network upgrade","type":"news_article","credibility":2},{"url":"https://shieldedlabs.net/the-orchard-counterfeiting-vulnerability/","name":"Shielded Labs: The Orchard Counterfeiting Vulnerability","type":"official","credibility":1},{"url":"https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years","name":"CoinDesk: Zcash plummets 38% as Shielded Labs reveals a major bug that went undetected for four years","type":"news_article","credibility":1}],"severity":"medium"},{"content":"The incident exposed a basic tension in shielded cryptocurrency design. Orchard uses zero-knowledge proofs to guarantee transaction privacy, and that same property makes it impossible to audit the pool's internal state for anomalies. On transparent ledgers such as Bitcoin and Ethereum, anyone can verify total supply at any time, and inflation from a bug would show up in the public transaction graph. Zcash's shielded pools do not allow this, so any soundness flaw that lets invalid proofs through creates a class of attack that on-chain analysis cannot detect after the fact. Arthur Hayes made this point when he exited, saying privacy-first systems demand architectural perfection. The halo2 library underlying the Orchard circuit is used across the wider zero-knowledge proof ecosystem beyond Zcash. Researchers noted that under-constrained circuit elements are among the most common vulnerability classes in production ZK systems; Kudelski Security's analyses estimate that over 80% of ZK audit findings trace to the circuit layer. Aztec Labs CEO Joe Andrews said formal circuit verification combined with a secondary proof system is the best long-term mitigation for this class of flaw. Hornby used Claude Opus 4.8 within about a day of its release to find a flaw that had resisted four years of expert review. This prompted commentary on the changing economics of vulnerability discovery. Bloomberg described the incident as showing the 'scale of AI-hacking threat' to cryptographic systems, noting that AI-assisted auditing can be used by attackers as well as defenders.","heading":"Structural risk: privacy architecture vs supply auditability","sources":[{"url":"https://www.bloomberg.com/news/articles/2026-06-14/crypto-token-s-50-wipeout-shows-magnitude-of-ai-hacking-threat","name":"Bloomberg: Crypto Token's 50% Wipeout Shows Scale of AI-Hacking Threat","type":"news_article","credibility":1},{"url":"https://cryptonews.com/news/david-schwartz-ripple-zcash-orchard-vulnerability/","name":"CryptoNews: Ripple CTO Says Zcash is Safe: But Fake ZEC Bug Not Disproven","type":"news_article","credibility":2},{"url":"https://www.coindesk.com/markets/2026/06/05/arthur-hayes-dumps-zcash-holdings-after-orchard-pool-vulnerability-revealed","name":"CoinDesk: Arthur Hayes dumps Zcash holdings after Orchard Pool vulnerability revealed","type":"news_article","credibility":1},{"url":"https://blocksec.com/blog/web3-security-zcash-orchard-soundness-bug-analysis","name":"BlockSec: Zcash Orchard Soundness Bug Analysis","type":"research","credibility":2},{"url":"https://www.cryptoisac.org/news-member-content/the-zcash-orchard-bug-and-the-new-economics-of-vulnerability-discovery","name":"CryptoISAC: The Zcash Orchard Bug and the New Economics of Vulnerability Discovery","type":"research","credibility":2},{"url":"https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability","name":"Decrypt: ZEC Crashes 38% as Zcash Discloses 'Critical Counterfeiting Vulnerability'","type":"news_article","credibility":2},{"url":"https://thedefiant.io/news/blockchains/shielded-labs-proposes-new-zcash-upgrade-to-prove-zec-supply-after-orchard-bug","name":"The Defiant: Shielded Labs Proposes New Zcash Upgrade to Prove ZEC Supply After Orchard Bug","type":"news_article","credibility":2},{"url":"https://unchainedcrypto.com/ai-assisted-audit-uncovers-critical-zcash-orchard-vulnerability-that-could-have-minted-unlimited-counterfeit-zec/","name":"Unchained Crypto: AI-Assisted Audit Uncovers Critical Zcash Orchard Vulnerability","type":"news_article","credibility":2},{"url":"https://beincrypto.com/zcash-zec-orchard-counterfeiting-bug/","name":"BeInCrypto: An Opus 4.8 Audit Uncovered Zcash's Bug","type":"news_article","credibility":2}],"severity":"high"},{"content":"The SEC had previously investigated the Zcash Foundation and closed that investigation in January 2026 without enforcement action, removing a major regulatory overhang several months before the vulnerability surfaced. As of June 17, 2026, no regulatory, law enforcement or other official response specific to the Orchard vulnerability had been reported. The incident involves no allegations of fraud by Zcash developers; it was a cryptographic implementation flaw that has since been patched.","heading":"Regulatory background","sources":[{"url":"https://www.cryptotimes.io/2026/06/02/zcash-executes-emergency-fork-after-critical-orchard-vulnerability-discovery/","name":"Crypto Times: Zcash Executes Emergency Fork After Critical Orchard Vulnerability Discovery","type":"news_article","credibility":2}],"severity":"low"}],"timeline":[{"date":"2022-05","event":"The Orchard shielded pool activates on mainnet through the NU5 upgrade, introducing the Halo 2 proving system. The soundness flaw in the halo2_gadgets scalar multiplication gadget is present from launch.","source":"Zcash Foundation / Shielded Labs / CoinDesk","source_url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/"},{"date":"2025-08","event":"ZEC reaches a cycle low of about $35.","source":"BitMEX Blog","source_url":"https://www.bitmex.com/blog/zec-crash-2026"},{"date":"2026-01","event":"The SEC closes its investigation into the Zcash Foundation without enforcement action.","source":"Crypto Times","source_url":"https://www.cryptotimes.io/2026/06/02/zcash-executes-emergency-fork-after-critical-orchard-vulnerability-discovery/"},{"date":"2026-04","event":"Shielded Labs engages Taylor Hornby as an independent security engineer for a targeted protocol audit of Zcash.","source":"CoinDesk / Unchained Crypto","source_url":"https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years"},{"date":"2026-05","event":"ZEC rises about 91% from May 1 to a late-May peak of about $670.","source":"BitMEX Blog","source_url":"https://www.bitmex.com/blog/zec-crash-2026"},{"date":"2026-05","event":"On May 28, Anthropic publicly releases the Claude Opus 4.8 model.","source":"BeInCrypto / Unchained Crypto","source_url":"https://beincrypto.com/zcash-zec-orchard-counterfeiting-bug/"},{"date":"2026-05","event":"On May 29, Taylor Hornby finds the Orchard circuit soundness flaw using Claude Opus 4.8 and a custom AI auditing harness. He builds a working exploit that generates unlimited counterfeit ZEC in a local regtest environment and discloses it to ZODL engineers that evening.","source":"The Block / CoinDesk / Crypto Times","source_url":"https://www.theblock.co/post/403698/zcash-vulnerability-zec-drops"},{"date":"2026-05","event":"On May 30, ZODL engineers Daira-Emma Hopwood, Kris Nuttycombe and Jack Grigg confirm the vulnerability, and ZODL executive Josh Swihart joins a secure coordination call. Emergency response planning begins.","source":"Crypto Times","source_url":"https://www.cryptotimes.io/2026/06/08/inside-zcashs-50-hour-race-to-save-orchard-from-exploit/"},{"date":"2026-05","event":"On May 31, private coordination with miners, exchanges and node operators begins.","source":"Zcash Foundation","source_url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/"},{"date":"2026-06","event":"The emergency soft fork is prepared in Zebra 4.5.3. Activation is delayed because miners have too little time to deploy it, and coordination with the mining pools ViaBTC and Foundry continues.","source":"Crypto Times","source_url":"https://www.cryptotimes.io/2026/06/08/inside-zcashs-50-hour-race-to-save-orchard-from-exploit/"},{"date":"2026-06","event":"The emergency soft fork activates at mainnet block height 3,363,426 (about 02:00 UTC on June 2 per the Zcash Foundation; 22:30 EDT on June 1 per another account), disabling all Orchard-containing transactions. ZODL releases zcashd v6.12.5.","source":"Zcash Foundation / Crypto Times","source_url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/"},{"date":"2026-06","event":"A 25-block fork (heights 3,363,431-3,363,455) with 37 orphaned blocks occurs as nodes run outdated software, resolving in favor of the patched chain. Accounts place it at the June 2 soft fork or the June 3 NU6.2 switchover.","source":"Crypto Times / Crypto Economy","source_url":"https://crypto-economy.com/zcash-pushes-emergency-update-to-patch-orchard-bug-network-briefly-unstable/"},{"date":"2026-06","event":"On June 3, the NU6.2 hard fork activates at block height 3,364,600 (00:05 EDT) via Zebra 5.0.0, re-enabling Orchard with the corrected circuit and a new consensus rule rejecting non-canonical proof sizes. Testnet activates at block 4,052,000. ZEC rallies from about $544 to about $624.","source":"Zcash Foundation / CoinTelegraph","source_url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/"},{"date":"2026-06","event":"On June 4, ZEC trades at a local high of about $624-$635, depending on the source.","source":"Decrypt / BitMEX Blog","source_url":"https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability"},{"date":"2026-06","event":"On June 5, Shielded Labs publishes its public disclosure (written by Jason McGee). ZEC falls about 38% in 24 hours and about 50% over 48 hours, to a low of about $309, and trading volume drops about 57%.","source":"CoinDesk / Decrypt / CryptoBriefing","source_url":"https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years"},{"date":"2026-06","event":"On June 5, Arthur Hayes publicly says he has liquidated his entire ZEC position because it cannot be ruled out cryptographically that the flaw was exploited.","source":"CoinDesk","source_url":"https://www.coindesk.com/markets/2026/06/05/arthur-hayes-dumps-zcash-holdings-after-orchard-pool-vulnerability-revealed"},{"date":"2026-06","event":"On June 5, Shielded Labs proposes a network upgrade creating a new shielded pool with turnstile accounting on all existing Orchard coins.","source":"The Defiant","source_url":"https://thedefiant.io/news/blockchains/shielded-labs-proposes-new-zcash-upgrade-to-prove-zec-supply-after-orchard-bug"},{"date":"2026-06","event":"On June 8, developers propose the Ironwood network upgrade, targeted for late July 2026, and ZEC rebounds about 45% from its post-disclosure low. A detailed post-mortem of the 50-hour response is published the same day.","source":"CoinDesk / Crypto Times","source_url":"https://www.coindesk.com/markets/2026/06/08/zcash-bounces-45-as-developers-propose-new-ironwood-upgrade"},{"date":"2026-06","event":"On June 14, Bloomberg publishes analysis describing the incident as showing the 'scale of AI-hacking threat' to cryptographic systems.","source":"Bloomberg","source_url":"https://www.bloomberg.com/news/articles/2026-06-14/crypto-token-s-50-wipeout-shows-magnitude-of-ai-hacking-threat"},{"date":"2026-06","event":"On June 15, Zcash founder Zooko Wilcox explains how Ironwood's turnstiles will work as a live supply audit during migration, and Shielded Labs updates its original disclosure post.","source":"Crypto Times / Shielded Labs","source_url":"https://www.cryptotimes.io/2026/06/15/how-zcashs-ironwood-turnstiles-will-trap-counterfeit-coins/"}],"sources_used":[{"url":"https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/","name":"Zcash Foundation: Zebra 4.5.3 and 5.0.0 Emergency Soft Fork and NU6.2 Activation","type":"official","archive_url":"http://web.archive.org/web/20260603172312/https://zfnd.org/zebra-4-5-3-and-5-0-0-emergency-soft-fork-and-nu6-2-activation/","credibility":1,"archive_timestamp":null},{"url":"https://forum.zcashcommunity.com/t/the-orchard-counterfeiting-vulnerability-and-next-steps/56015","name":"Zcash Community Forum: The Orchard Counterfeiting Vulnerability and Next Steps","type":"official","archive_url":"http://web.archive.org/web/20260709182109/https://forum.zcashcommunity.com/t/the-orchard-counterfeiting-vulnerability-and-next-steps/56015","credibility":1,"archive_timestamp":null},{"url":"https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years","name":"CoinDesk: Zcash plummets 38% as Shielded Labs reveals a major bug that went undetected for four years","type":"news_article","archive_url":"http://web.archive.org/web/20260623212251/https://www.coindesk.com/markets/2026/06/05/zcash-plummets-30-as-developer-reveals-a-major-bug-that-went-undetected-for-four-years","credibility":1,"archive_timestamp":null},{"url":"https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability","name":"Decrypt: ZEC Crashes 38% as Zcash Discloses 'Critical Counterfeiting Vulnerability'","type":"news_article","archive_url":"http://web.archive.org/web/20260717050635/https://decrypt.co/370105/zec-crashes-38-as-zcash-discloses-critical-counterfeiting-vulnerability","credibility":2,"archive_timestamp":null},{"url":"https://www.theblock.co/post/403698/zcash-vulnerability-zec-drops","name":"The Block: Security researcher finds Zcash vulnerability allowing 'unlimited' counterfeit minting","type":"news_article","archive_url":"https://web.archive.org/web/20260726161445/https://www.theblock.co/post/403698/zcash-vulnerability-zec-drops","credibility":2,"archive_timestamp":null},{"url":"https://www.cryptotimes.io/2026/06/03/zcash-activates-nu6-2-hard-fork-following-double-spend-risk-discovery/","name":"Crypto Times: Zcash Activates NU6.2 Hard Fork Following Double-Spend Risk Discovery","type":"news_article","archive_url":"https://web.archive.org/web/20260726102812/https://www.cryptotimes.io/2026/06/03/zcash-activates-nu6-2-hard-fork-following-double-spend-risk-discovery/","credibility":2,"archive_timestamp":null},{"url":"https://www.cryptotimes.io/2026/06/02/zcash-executes-emergency-fork-after-critical-orchard-vulnerability-discovery/","name":"Crypto Times: Zcash Executes Emergency Fork After Critical Orchard Vulnerability Discovery","type":"news_article","archive_url":"http://web.archive.org/web/20260604173713/https://www.cryptotimes.io/2026/06/02/zcash-executes-emergency-fork-after-critical-orchard-vulnerability-discovery/","credibility":2,"archive_timestamp":null},{"url":"https://www.cryptotimes.io/2026/06/08/inside-zcashs-50-hour-race-to-save-orchard-from-exploit/","name":"Crypto Times: Inside Zcash's 50-Hour Race to Save Orchard From Exploit","type":"news_article","archive_url":"https://web.archive.org/web/20260726230303/https://www.cryptotimes.io/2026/06/08/inside-zcashs-50-hour-race-to-save-orchard-from-exploit/","credibility":2,"archive_timestamp":null},{"url":"https://www.blockhead.co/2026/06/05/zcash-founder-discloses-critical-orchard-forgery-flaw-fixed-by-emergency-hard-fork/","name":"Blockhead: Claude AI Finds Critical Vulnerability in Zcash","type":"news_article","archive_url":"http://web.archive.org/web/20260605135533/https://www.blockhead.co/2026/06/05/zcash-founder-discloses-critical-orchard-forgery-flaw-fixed-by-emergency-hard-fork/","credibility":2,"archive_timestamp":null},{"url":"https://cryptobriefing.com/zcash-plunges-counterfeiting-vulnerability/","name":"CryptoBriefing: Zcash plunges 38% after critical counterfeiting vulnerability 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Vulnerability'","type":"news_article","archive_url":"http://web.archive.org/web/20260611185256/https://finance.yahoo.com/markets/crypto/articles/zec-crashes-38-zcash-discloses-104159962.html","credibility":2,"archive_timestamp":null},{"url":"https://www.techtimes.com/articles/317831/20260605/why-crypto-crashing-ai-assisted-audit-exposes-four-year-zcash-orchard-bug-zec-plummets-31.htm","name":"TechTimes: AI-Assisted Audit Exposes Four-Year Zcash Orchard Bug","type":"news_article","archive_url":"http://web.archive.org/web/20260611070616/https://www.techtimes.com/articles/317831/20260605/why-crypto-crashing-ai-assisted-audit-exposes-four-year-zcash-orchard-bug-zec-plummets-31.htm","credibility":2,"archive_timestamp":null},{"url":"https://shieldedlabs.net/the-orchard-counterfeiting-vulnerability/","name":"Shielded Labs: The Orchard Counterfeiting Vulnerability (official disclosure, authored by Jason McGee)","type":"official","archive_url":"http://web.archive.org/web/20260720141528/https://shieldedlabs.net/the-orchard-counterfeiting-vulnerability/","credibility":1,"archive_timestamp":null},{"url":"https://www.coindesk.com/markets/2026/06/05/arthur-hayes-dumps-zcash-holdings-after-orchard-pool-vulnerability-revealed","name":"CoinDesk: Arthur Hayes dumps Zcash holdings after Orchard Pool vulnerability revealed","type":"news_article","archive_url":"http://web.archive.org/web/20260624161712/https://www.coindesk.com/markets/2026/06/05/arthur-hayes-dumps-zcash-holdings-after-orchard-pool-vulnerability-revealed","credibility":1,"archive_timestamp":null},{"url":"https://www.coindesk.com/markets/2026/06/08/zcash-bounces-45-as-developers-propose-new-ironwood-upgrade","name":"CoinDesk: Zcash bounces 45% as developers propose new Ironwood upgrade","type":"news_article","archive_url":"http://web.archive.org/web/20260627224312/https://www.coindesk.com/markets/2026/06/08/zcash-bounces-45-as-developers-propose-new-ironwood-upgrade","credibility":1,"archive_timestamp":null},{"url":"https://www.bloomberg.com/news/articles/2026-06-14/crypto-token-s-50-wipeout-shows-magnitude-of-ai-hacking-threat","name":"Bloomberg: Crypto Token's 50% Wipeout Shows Scale of AI-Hacking Threat","type":"news_article","archive_url":null,"credibility":1,"archive_timestamp":null},{"url":"https://unchainedcrypto.com/ai-assisted-audit-uncovers-critical-zcash-orchard-vulnerability-that-could-have-minted-unlimited-counterfeit-zec/","name":"Unchained Crypto: AI-Assisted Audit Uncovers Critical Zcash Orchard Vulnerability","type":"news_article","archive_url":"http://web.archive.org/web/20260605104931/https://unchainedcrypto.com/ai-assisted-audit-uncovers-critical-zcash-orchard-vulnerability-that-could-have-minted-unlimited-counterfeit-zec/","credibility":2,"archive_timestamp":null},{"url":"https://cryptobriefing.com/zcash-orchard-pool-withdrawal-counterfeiting-bug/","name":"CryptoBriefing: Zcash's Orchard pool sees 1% withdrawal as counterfeiting bug shakes investor confidence","type":"news_article","archive_url":"https://web.archive.org/web/20260727053015/https://cryptobriefing.com/zcash-orchard-pool-withdrawal-counterfeiting-bug/","credibility":2,"archive_timestamp":null},{"url":"https://www.cryptotimes.io/2026/06/15/how-zcashs-ironwood-turnstiles-will-trap-counterfeit-coins/","name":"CryptoTimes: Zcash Orchard Vulnerability: Zooko Explains Why Ironwood 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