{"id":"CVE-2026-109363","title":"ZcashFoundation Zebra 6.4.0 before 6.4.2 parses version 6 transactions carrying a pre-NU6.3 consensus branch ID, but the size computation during UnminedTx construction treats re-serialization of the Orchard bundle as infallible, so the r…","summary":"ZcashFoundation Zebra 6.4.0 before 6.4.2 parses version 6 transactions carrying a pre-NU6.3 consensus branch ID, but the size computation during UnminedTx construction treats re-serialization of the Orchard bundle as infallible, so the r…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-617"],"published":"2026-10-12","updated":"2026-10-12","sourceUpdated":"2026-10-12T17:17:33.953","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-109363","references":[{"url":"https://github.com/ZcashFoundation/zebra/commit/008abac5c99e872f283450d596d95e37851df49a","label":"disclosure@vulncheck.com"},{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-h5rr-8pqv-grp9","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/zebra-6.4.0-before-6.4.2-denial-of-service-via-malformed-v6-transaction","label":"disclosure@vulncheck.com"}],"tags":["nvd"],"ingestedAt":"2026-10-12T18:00:08.214Z","slug":"CVE-2026-109363","body":"## Overview\n\nZcashFoundation Zebra 6.4.0 before 6.4.2 parses version 6 transactions carrying a pre-NU6.3 consensus branch ID, but the size computation during UnminedTx construction treats re-serialization of the Orchard bundle as infallible, so the resulting error trips an expect that aborts zebrad. Unauthenticated peers can send a single pre-handshake tx message to crash the node, and can repeat this after each restart.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}