{"id":"CVE-2026-109363","published":"2026-10-12T17:17:33.953","lastModified":"2026-10-15T20:31:47.127","description":"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 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.","cvssScore":7.5,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwes":["CWE-617"],"vendors":[],"products":[],"references":[{"url":"https://github.com/ZcashFoundation/zebra/commit/008abac5c99e872f283450d596d95e37851df49a","tags":[]},{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-h5rr-8pqv-grp9","tags":[]},{"url":"https://www.vulncheck.com/advisories/zebra-6.4.0-before-6.4.2-denial-of-service-via-malformed-v6-transaction","tags":[]}],"exploitRefs":[{"url":"https://github.com/ZcashFoundation/zebra/commit/008abac5c99e872f283450d596d95e37851df49a","tags":[]},{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-h5rr-8pqv-grp9","tags":[]}],"hasPoc":true,"ai":null}