{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-35042",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-03-31T21:06:06.428Z",
        "datePublished": "2026-04-06T17:02:12.180Z",
        "dateUpdated": "2026-04-07T15:59:49.872Z"
    },
    "containers": {
        "cna": {
            "title": "fast-jwt accepts unknown `crit` header extensions (RFC 7515 §4.1.11 MUST violation)",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-345",
                            "lang": "en",
                            "description": "CWE-345: Insufficient Verification of Data Authenticity",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-636",
                            "lang": "en",
                            "description": "CWE-636: Not Failing Securely ('Failing Open')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "HIGH",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6"
                },
                {
                    "name": "https://www.rfc-editor.org/rfc/rfc7515.html#section-4.1.11",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://www.rfc-editor.org/rfc/rfc7515.html#section-4.1.11"
                }
            ],
            "affected": [
                {
                    "vendor": "nearform",
                    "product": "fast-jwt",
                    "versions": [
                        {
                            "version": "<= 6.1.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-04-06T17:02:12.180Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC."
                }
            ],
            "source": {
                "advisory": "GHSA-hm7r-c7qw-ghp6",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-04-07T15:19:36.239438Z",
                                "id": "CVE-2026-35042",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-04-07T15:59:49.872Z"
                }
            }
        ]
    }
}