{
    "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": "2026-07-24T03:55:58.915Z"
    },
    "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": "2026-07-23T00:00:00+00:00",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3",
                                "id": "CVE-2026-56820"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-07-24T03:55:58.915Z"
                }
            }
        ]
    }
}