{"id":"CVE-2026-40880","state":"PUBLISHED","title":"Zebra: Cached Mempool Verification Bypasses Consensus Rules for Ahead-of-Tip Blocks","description":"ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.1 and zebra-consensus version 5.0.2, a logic error in Zebra's transaction verification cache could allow a malicious miner to induce a consensus split. By carefully submitting a transaction that is valid for height H+1 but invalid for H+2 and then mining that transaction in a block at height H+2, a miner could cause vulnerable Zebra nodes to accept an invalid block, leading to a consensus split from the rest of the Zcash network. This vulnerability is fixed in zebrad version 4.3.1 and zebra-consensus version 5.0.2.","publishedAt":"2026-04-21T19:18:22.657Z","updatedAt":"2026-04-21T19:52:58.880Z","severity":{"score":7.2,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["ZcashFoundation zebrad","ZcashFoundation zebra-consensus"],"affected":[{"vendor":"ZcashFoundation","product":"zebrad","versions":[{"version":"< 4.3.1","status":"affected"}]},{"vendor":"ZcashFoundation","product":"zebra-consensus","versions":[{"version":"< 5.0.2","status":"affected"}]}],"references":["https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-xvj8-ph7x-65gf"],"weaknesses":["CWE-1025"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40880.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40880","state":"PUBLISHED","datePublished":"2026-04-21T19:18:22.657Z","dateUpdated":"2026-04-21T19:52:58.880Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-15T15:57:41.719Z"},"containers":{"cna":{"title":"Zebra: Cached Mempool Verification Bypasses Consensus Rules for Ahead-of-Tip Blocks","descriptions":[{"lang":"en","value":"ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.1 and zebra-consensus version 5.0.2, a logic error in Zebra's transaction verification cache could allow a malicious miner to induce a consensus split. By carefully submitting a transaction that is valid for height H+1 but invalid for H+2 and then mining that transaction in a block at height H+2, a miner could cause vulnerable Zebra nodes to accept an invalid block, leading to a consensus split from the rest of the Zcash network. This vulnerability is fixed in zebrad version 4.3.1 and zebra-consensus version 5.0.2."}],"affected":[{"vendor":"ZcashFoundation","product":"zebrad","versions":[{"version":"< 4.3.1","status":"affected"}]},{"vendor":"ZcashFoundation","product":"zebra-consensus","versions":[{"version":"< 5.0.2","status":"affected"}]}],"references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-xvj8-ph7x-65gf","name":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-xvj8-ph7x-65gf","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"HIGH","subAvailabilityImpact":"HIGH","baseScore":7.2,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1025","lang":"en","description":"CWE-1025: Comparison Using Wrong Factors","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-21T19:18:22.657Z"},"source":{"advisory":"GHSA-xvj8-ph7x-65gf","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-21T19:52:38.860835Z","id":"CVE-2026-40880","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":"2026-04-21T19:52:58.880Z"}}]}}}