{"id":"CVE-2026-123555","title":"Zebra 2.3.0 before 7.0.0 Denial of Service via Unscored Script Verification Failures","summary":"Zebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade misbehavior scoring by sending transactions or blocks with invalid transparent scripts. Attackers can flood mempool with …","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","cvssSource":"cna","cwe":["CWE-755"],"vendor":"ZcashFoundation","product":"zebra","affected":["zebra >= 2.3.0 < 7.0.0","zebra >= 1.0.0-beta.46 < 18.0.0"],"published":"2026-11-08","updated":"2026-11-08","sourceUpdated":"2026-11-08T01:37:57.593Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-123555","references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-jq45-ghw5-v37x","label":"GitHub Security Advisory (GHSA-jq45-ghw5-v37x)"},{"url":"https://github.com/ZcashFoundation/zebra/commit/e8db87eb69254e0d4eedd058eadd48bdfa09065a","label":"Patch Commit"},{"url":"https://www.vulncheck.com/advisories/zebra-2.3.0-before-7.0.0-denial-of-service-via-unscored-script-verification-failures","label":"VulnCheck Advisory: Zebra 2.3.0 before 7.0.0 Denial of Service via Unscored Script Verification Failures"}],"tags":["cve.org"],"ingestedAt":"2026-11-08T02:43:18.667Z","slug":"CVE-2026-123555","body":"## Overview\n\nZebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade misbehavior scoring by sending transactions or blocks with invalid transparent scripts. Attackers can flood mempool with script-failing transactions or serve forged v5 block bodies with altered scriptSig bytes to exhaust CPU and repeatedly stall block sync.\n\n## Affected\n\n- `zebra >= 2.3.0 < 7.0.0`\n- `zebra >= 1.0.0-beta.46 < 18.0.0`\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":[]}