CVE-2026-56820

{"id": "CVE-2026-56820", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-56820", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-07-24T03:55:59.408001Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.4, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 2.2}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "netty", "product": "netty", "versions": [{"status": "affected", "version": ">= 4.2.0.Final, < 4.2.16.Final"}, {"status": "affected", "version": "< 4.1.136.Final"}]}]}], "published": "2026-07-21T23:17:52.403", "references": [{"url": "https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/netty/netty/security/advisories/GHSA-272m-gcwp-mpwg", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-295"}]}], "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."}], "lastModified": "2026-07-30T14:48:49.323", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3A15093F-C6A7-4FCF-81BA-939CD522D1DD", "versionEndExcluding": "4.1.136"}, {"criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4DE4BC35-4405-49B5-A2A8-A700C7F63C8B", "versionEndExcluding": "4.2.16", "versionStartIncluding": "4.2.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}