{"id":"CVE-2026-104431","summary":"Zebra before 6.0.0 Denial of Service via Synchronous Script FFI Verification","details":"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-standard high-sigop P2SH transactions that reach CachedFfiTransaction::is_valid() before standardness checks, saturating the verifier buffer and rendering the node unresponsive.","aliases":["GHSA-84j3-rw4c-gqmj"],"modified":"2026-10-04T02:46:34.773624450Z","published":"2026-10-02T11:38:10.560Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-405"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104431.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104431.json"},{"type":"ADVISORY","url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-84j3-rw4c-gqmj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-104431"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/zebra-before-6.0.0-denial-of-service-via-synchronous-script-ffi-verification"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/zcashfoundation/zebra","events":[{"introduced":"0"},{"fixed":"bb41d69013edbfa8594bb097fa751f47eeb31445"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"6.0.0"}],"source":["AFFECTED_FIELD","DESCRIPTION"]}}],"versions":["v6.0.0-rc.0","v5.2.0","v5.1.0","v5.1.1","v5.0.0","v4.5.1","v4.5.0","v4.4.0","v4.4.1","v4.3.1","4.3.1","v4.3.0","v4.2.0","v4.1.0","v4.0.0","v3.1.0","v3.0.0","v3.0.0-rc.0","v2.5.0","v2.0.1","v2.4.2","v2.3.0","v2.4.0","v2.0.0","v2.2.0","v2.1.0","v2.0.0-rc.0","v1.9.0","v1.8.0","v1.7.0","v1.6.1","v1.6.0","v1.5.2","v1.5.1","v1.5.0","v1.4.0","v1.3.0","v1.2.0","v1.1.0","v1.0.1","v1.0.0","v1.0.0-rc.9","v1.0.0-rc.8","v1.0.0-rc.7","v1.0.0-rc.6","v1.0.0-rc.5","v1.0.0-rc.0","v1.0.0-rc.4","v1.0.0-rc.3","v1.0.0-rc.2","v1.0.0-rc.1","v1.0.0-beta.15","v1.0.0-beta.14","v1.0.0-beta.13","v1.0.0-beta.12","v1.0.0-beta.11","v1.0.0-beta.10","v1.0.0-beta.9","v1.0.0-beta.8","v1.0.0-beta.7","v1.0.0-beta.6","v1.0.0-beta.5","v1.0.0-beta.4","v1.0.0-beta.3","v1.0.0-beta.2","v1.0.0-beta.1","v1.0.0-beta.0","v1.0.0-alpha.19","v1.0.0-alpha.18","v1.0.0-alpha.17","v1.0.0-alpha.16","v1.0.0-alpha.15","v1.0.0-alpha.14","v1.0.0-alpha.13","v1.0.0-alpha.12","v1.0.0-alpha.11","v1.0.0-alpha.10","v1.0.0-alpha.9","v1.0.0-alpha.8","v1.0.0-alpha.7","v1.0.0-alpha.6","v1.0.0-alpha.5","v1.0.0-alpha.4","v1.0.0-alpha.3","v1.0.0-alpha.2","v1.0.0-alpha.1","v1.0.0-alpha.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-104431.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}