{"id":"CVE-2026-104436","state":"PUBLISHED","title":"Zebra before 4.5.0 CPU Amplification via Uncapped getblocks/getheaders Locator Length","description":"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 with up to 65,535 locator hashes, triggering per-hash chain lookups that degrade block validation, RPC, and mempool performance.","publishedAt":"2026-10-02T11:38:13.172Z","updatedAt":"2026-10-29T21:15:28.872Z","severity":{"score":6.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["ZcashFoundation zebra","ZcashFoundation zebra-chain"],"affected":[{"vendor":"ZcashFoundation","product":"zebra","packageURL":"pkg:cargo/zebrad","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"4.5.0","versionType":"semver"},{"version":"4.5.0","status":"unaffected","versionType":"semver"}]},{"vendor":"ZcashFoundation","product":"zebra-chain","packageURL":"pkg:cargo/zebra-chain","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"8.0.0","versionType":"semver"},{"version":"8.0.0","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-443g-gwgp-49x4","https://www.vulncheck.com/advisories/zebra-before-4.5.0-cpu-amplification-via-uncapped-getblocks-getheaders-locator-length"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T23:08:31.977Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/104xxx/CVE-2026-104436.json","commit":"dc7676b3f67d6707e4927968546e7e0125ff7ec7","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-104436","state":"PUBLISHED","datePublished":"2026-10-02T11:38:13.172Z","dateUpdated":"2026-10-29T21:15:28.872Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-10-02T00:50:26.604Z"},"containers":{"cna":{"title":"Zebra before 4.5.0 CPU Amplification via Uncapped getblocks/getheaders Locator Length","descriptions":[{"lang":"en","value":"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 with up to 65,535 locator hashes, triggering per-hash chain lookups that degrade block validation, RPC, and mempool performance."}],"affected":[{"vendor":"ZcashFoundation","product":"zebra","packageURL":"pkg:cargo/zebrad","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"4.5.0","versionType":"semver"},{"version":"4.5.0","status":"unaffected","versionType":"semver"}]},{"vendor":"ZcashFoundation","product":"zebra-chain","packageURL":"pkg:cargo/zebra-chain","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"8.0.0","versionType":"semver"},{"version":"8.0.0","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-443g-gwgp-49x4","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-443g-gwgp-49x4)"},{"url":"https://www.vulncheck.com/advisories/zebra-before-4.5.0-cpu-amplification-via-uncapped-getblocks-getheaders-locator-length","name":"VulnCheck Advisory: Zebra before 4.5.0 CPU Amplification via Uncapped getblocks/getheaders Locator Length","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.3,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW","baseScore":3.7,"baseSeverity":"LOW"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-29T21:15:28.872Z"},"datePublic":"2026-05-29T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:zfnd:zebra:*:*:*:*:*:*:*:*","versionEndExcluding":"4.5.0"},{"vulnerable":true,"criteria":"cpe:2.3:a:zfnd:zebra-chain:*:*:*:*:*:*:*:*","versionEndExcluding":"8.0.0"}]}]}],"credits":[{"lang":"en","value":"dingledropper","type":"reporter"},{"lang":"en","value":"mpguerra","type":"coordinator"},{"lang":"en","value":"oxarbitrage","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-02T14:51:19.938453Z","id":"CVE-2026-104436","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-02T14:51:28.130Z"}}]}}}