{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-120459", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-11-02T12:42:23.406Z", "datePublished": "2026-11-02T14:29:15.767Z", "dateUpdated": "2026-11-02T14:29:15.767Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-11-02T14:29:15.767Z"}, "datePublic": "2026-03-08T00:00:00.000Z", "title": "python-jose through 3.5.0 Authentication Bypass via Empty HMAC Key", "descriptions": [{"lang": "en", "value": "python-jose through 3.5.0 contains an authentication bypass vulnerability that allows unauthenticated attackers to forge JWTs because HMACKey and CryptographyHMACKey accept zero-length HMAC secrets. When an application's HS256/HS384/HS512 verification key resolves to empty, such as an oct JWK with empty k, attackers can forge tokens with arbitrary claims that jwt.decode accepts."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Improper Verification of Cryptographic Signature", "cweId": "CWE-347", "type": "CWE"}]}], "affected": [{"vendor": "mpdavis", "product": "python-jose", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThanOrEqual": "3.5.0", "status": "affected", "versionType": "semver"}], "packageURL": "pkg:pypi/python-jose", "repo": "https://github.com/mpdavis/python-jose"}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:python-jose_project:python-jose:*:*:*:*:*:*:*:*", "versionEndIncluding": "3.5.0"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 9.1, "baseSeverity": "CRITICAL"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE", "baseScore": 7.4, "baseSeverity": "HIGH"}}], "references": [{"url": "https://github.com/mpdavis/python-jose/issues/398", "tags": ["issue-tracking"]}, {"url": "https://github.com/mpdavis/python-jose/blob/3.5.0/jose/backends/native.py", "tags": ["technical-description"]}, {"url": "https://github.com/mpdavis/python-jose/blob/3.5.0/jose/backends/cryptography_backend.py", "tags": ["technical-description"]}, {"name": "VulnCheck Advisory: python-jose through 3.5.0 Authentication Bypass via Empty HMAC Key", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/python-jose-through-3.5.0-authentication-bypass-via-empty-hmac-key"}], "credits": [{"lang": "en", "value": "Gavin Blacklock", "type": "finder"}, {"lang": "en", "value": "Conner Webber", "type": "finder"}], "x_generator": {"engine": "vulncheck-endgame"}}}}