{"id":"CVE-2026-104436","title":"Zebra before 4.5.0 contains an uncontrolled resource consumption vulnerability that allows remote P2P peers to exhaust blocking-pool threads by sending oversized block locator vectors","summary":"Zebra before 4.5.0 contains an uncontrolled resource consumption vulnerability that allows remote P2P peers to exhaust blocking-pool threads by sending oversized block locator vectors. Attackers can send getblocks or getheaders messages …","severity":"low","cvss":3.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-770"],"vendor":"ZcashFoundation","product":"zebra","affected":["zebra < 4.5.0","zebra < 8.0.0"],"published":"2026-10-02","updated":"2026-10-02","sourceUpdated":"2026-10-02T17:59:09.430","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-104436","references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-443g-gwgp-49x4","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/zebra-before-4.5.0-cpu-amplification-via-uncapped-getblocks-getheaders-locator-length","label":"disclosure@vulncheck.com"},{"url":"https://github.com/ZcashFoundation/zebra/pull/10570"},{"url":"https://github.com/ZcashFoundation/zebra/commit/8981a1b95d4807cad99e5bb3b94fc8bc723ac033"},{"url":"https://github.com/ZcashFoundation/zebra"}],"tags":["nvd","cve.org","osv","rust"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-02T14:51:19.938453Z"},"ingestedAt":"2026-10-02T12:17:44.335Z","aliases":["GHSA-443g-gwgp-49x4"],"ecosystem":"rust","patched":["zebrad 4.5.0","zebra-chain 8.0.0"],"epss":0.00273,"epssPercentile":0.19564,"slug":"CVE-2026-104436","body":"## Overview\n\nZebra before 4.5.0 contains an uncontrolled resource consumption vulnerability that allows remote P2P peers to exhaust blocking-pool threads by sending oversized block locator vectors. Attackers can send getblocks or getheaders messages with up to 65,535 locator hashes, triggering per-hash chain lookups that degrade block validation, RPC, and mempool performance.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-104436)\n\nAffected packages:\n\n- `zebrad < 4.5.0`\n- `zebra-chain < 8.0.0`\n\nPatched in:\n\n- `zebrad 4.5.0`\n- `zebra-chain 8.0.0`\n\nSource: https://osv.dev/vulnerability/GHSA-443g-gwgp-49x4","depth":"sunlit","depthScore":20,"depthScoreParts":{"impact":20.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}