{"id":"CVE-2026-104431","title":"Zebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification","summary":"Zebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification. Attackers can send non-standar…","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-405"],"vendor":"ZcashFoundation","product":"zebra","affected":["zebra < 6.0.0"],"published":"2026-10-02","updated":"2026-10-02","sourceUpdated":"2026-10-02T12:17:13.610","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-104431","references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-84j3-rw4c-gqmj","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/zebra-before-6.0.0-denial-of-service-via-synchronous-script-ffi-verification","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-02T12:17:44.333Z","slug":"CVE-2026-104431","body":"## Overview\n\nZebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification. Attackers can send non-standard high-sigop P2SH transactions that reach CachedFfiTransaction::is_valid() before standardness checks, saturating the verifier buffer and rendering the node unresponsive.\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":[]}