{"id":"CVE-2026-109363","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-109363","generatedAt":"2026-10-28T01:12:03.282Z","title":"Unauthenticated peers can send a single pre-handshake tx message to crash the node, and can repeat this after each restart.","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.","published":"2026-10-12T17:17:34.000Z","lastModified":"2026-10-15T20:31:47.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-617"],"affected":[],"epss":{"score":0.00432,"percentile":0.37172,"date":"2026-10-26","history":[{"date":"2026-10-13","score":0.00432,"percentile":0.35638}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.43%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-12T17:17:34.000Z","detail":{"score":"8.7","severity":"HIGH","publishedAt":"2026-10-12T17:17:33.953Z"},"summary":"New CVE, high severity (CVSS 8.7)."}],"references":[{"url":"https://github.com/ZcashFoundation/zebra/commit/008abac5c99e872f283450d596d95e37851df49a","source":"disclosure@vulncheck.com"},{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-h5rr-8pqv-grp9","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/zebra-6.4.0-before-6.4.2-denial-of-service-via-malformed-v6-transaction","source":"disclosure@vulncheck.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-109363","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}