{"id":"CVE-2026-123556","title":"Zebra 4.5.0 before 7.0.0 Honest Peer Ban via Mempool Lock-Time Scoring","summary":"ZcashFoundation Zebra from 4.5.0 before 7.0.0 contains a protection mechanism failure that bans honest peers by scoring mempool lock-time rejections at the ban threshold. Attackers can broadcast transactions locked until the current heig…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cvssSource":"cna","cwe":["CWE-693"],"vendor":"ZcashFoundation","product":"zebra","affected":["zebra >= 4.5.0 < 7.0.0"],"published":"2026-11-08","updated":"2026-11-08","sourceUpdated":"2026-11-08T01:37:58.283Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-123556","references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-5h3r-fpmj-483w","label":"GitHub Security Advisory (GHSA-5h3r-fpmj-483w)"},{"url":"https://www.vulncheck.com/advisories/zebra-4.5.0-before-7.0.0-honest-peer-ban-via-mempool-lock-time-scoring","label":"VulnCheck Advisory: Zebra 4.5.0 before 7.0.0 Honest Peer Ban via Mempool Lock-Time Scoring"}],"tags":["cve.org"],"ingestedAt":"2026-11-08T02:43:18.666Z","slug":"CVE-2026-123556","body":"## Overview\n\nZcashFoundation Zebra from 4.5.0 before 7.0.0 contains a protection mechanism failure that bans honest peers by scoring mempool lock-time rejections at the ban threshold. Attackers can broadcast transactions locked until the current height right after each block, causing lagging nodes to ban honest relaying peers for 24 hours or until restart.\n\n## Affected\n\n- `zebra >= 4.5.0 < 7.0.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}