{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-56820","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-23T14:55:09.116Z","datePublished":"2026-07-21T22:26:16.588Z","dateUpdated":"2026-07-24T20:12:43.581Z"},"containers":{"cna":{"title":"Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks","problemTypes":[{"descriptions":[{"cweId":"CWE-295","lang":"en","description":"CWE-295: Improper Certificate Validation","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/netty/netty/security/advisories/GHSA-272m-gcwp-mpwg","tags":["x_refsource_CONFIRM"],"url":"https://github.com/netty/netty/security/advisories/GHSA-272m-gcwp-mpwg"},{"name":"https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b","tags":["x_refsource_MISC"],"url":"https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b"},{"name":"https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6","tags":["x_refsource_MISC"],"url":"https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6"},{"name":"https://github.com/netty/netty/releases/tag/netty-4.1.136.Final","tags":["x_refsource_MISC"],"url":"https://github.com/netty/netty/releases/tag/netty-4.1.136.Final"},{"name":"https://github.com/netty/netty/releases/tag/netty-4.2.16.Final","tags":["x_refsource_MISC"],"url":"https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"}],"affected":[{"vendor":"netty","product":"netty","versions":[{"version":">= 4.2.0.Final, < 4.2.16.Final","status":"affected"},{"version":"< 4.1.136.Final","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-07-21T22:26:16.588Z"},"descriptions":[{"lang":"en","value":"Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4.1.135.Final, `OcspClient` does not validate that the `CertificateID` in an OCSP response matches the requested `CertificateID`, which can lead to replay attack. `OcspClient.validateResponse` accepts a legitimately signed `GOOD` status response for an unrelated certificate issued by the same CA, allowing bypass of revocation checks for another certificate. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final."}],"source":{"advisory":"GHSA-272m-gcwp-mpwg","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-24T03:55:59.408001Z","id":"CVE-2026-56820","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-24T20:12:43.581Z"}}]}}