{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-102266",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-09-28T20:11:16.658Z",
        "datePublished": "2026-09-28T20:21:26.164Z",
        "dateUpdated": "2026-09-29T19:35:42.049Z"
    },
    "containers": {
        "cna": {
            "title": "PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-347",
                            "lang": "en",
                            "description": "CWE-347: Improper Verification of Cryptographic Signature",
                            "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/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r"
                },
                {
                    "name": "https://github.com/jpadilla/pyjwt/commit/f91ed44dd65baaf457f4b3353ed35e98a753934c",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/jpadilla/pyjwt/commit/f91ed44dd65baaf457f4b3353ed35e98a753934c"
                },
                {
                    "name": "https://github.com/jpadilla/pyjwt/releases/tag/2.14.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/jpadilla/pyjwt/releases/tag/2.14.0"
                }
            ],
            "affected": [
                {
                    "vendor": "jpadilla",
                    "product": "pyjwt",
                    "versions": [
                        {
                            "version": ">= 2.13.0, < 2.14.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-09-28T20:21:26.164Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.from_jwk is affected because PyJWK verification path used the decoded key without applying prepare_key validation. This occurs when a trusted JWK Set contains an oct entry with an empty k value. As a result, an attacker signs an HMAC token with the same zero-length key accepted by PyJWT. Consequently, forged token can carry arbitrary authenticated claims. This issue is fixed in version 2.14.0."
                }
            ],
            "source": {
                "advisory": "GHSA-9j54-fg26-wv3r",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-29T19:28:36.086597Z",
                                "id": "CVE-2026-102266",
                                "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": "2026-09-29T19:35:42.049Z"
                }
            }
        ]
    }
}