{"id":"EUVD-2026-61166","revision":"90ae0aea66d049e49779a760e0076f73","records":[{"revision":"90ae0aea66d049e49779a760e0076f73","observedAt":"2026-10-28T07:15:36.315+00:00","statement":{"source":"euvd","id":"EUVD-2026-61166","aliases":["CVE-2026-52735","GHSA-gf9r-m956-97qx"],"title":"ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, Zebra can accept a block that zcashd rejects because the P2SH signature-operation counter undercounts redeem scripts containing a disabled opcode followed by signature opcodes.…","description":"ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, Zebra can accept a block that zcashd rejects because the P2SH signature-operation counter undercounts redeem scripts containing a disabled opcode followed by signature opcodes. In zebra-script/src/lib.rs, p2sh_input_sigop_count used the pure-Rust script::Code::sig_op_count path, whose try_fold parser stops at disabled opcodes such as OP_CODESEPARATOR and returns only the partial count accumulated before the error. The zcashd reference implementation continues static signature-operation counting through disabled opcodes, so an attacker can broadcast P2SH spends that Zebra counts below MAX_BLOCK_SIGOPS while zcashd counts above the 20,000-operation limit. If a Zebra miner includes those transactions, Zebra validators accept the block while zcashd validators reject it, creating a consensus chain split that affects network integrity and availability without requiring the attacker to produce a block. This issue is fixed in version 4.5.0.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:H","score":9.3,"severity":null}],"references":["https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-gf9r-m956-97qx","https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd","https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-61166","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Aug 18, 2026, 7:23:10 PM","dateUpdated":"Aug 18, 2026, 7:48:45 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-61166","identifiers":["EUVD-2026-61166","CVE-2026-52735","GHSA-gf9r-m956-97qx"]},"retained":false,"historicalAffected":[]}],"coverage":[]}