{"id":"CVE-2026-120459","aliases":["DEBIAN-CVE-2026-120459","EUVD-2026-115219","GHSA-7jv8-hwmh-86qc","UBUNTU-CVE-2026-120459"],"status":"published","title":"python-jose through 3.5.0 Authentication Bypass via Empty HMAC Key","description":"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.","severity":{"version":"4.0","score":9.1,"vector":"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","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00251,"percentile":0.16621,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-347"],"published":"2026-11-02T14:29:15Z","modified":"2026-11-09T17:02:02Z","affected":[{"source":"osv","ecosystem":"Debian:12","package":"python-jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.0+dfsg-4","3.3.0+dfsg-5"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"python-jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.0+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"python-jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.0+dfsg-4"]}],"products":[{"vendor":"mpdavis","product":"python-jose"}],"references":[{"url":"https://github.com/mpdavis/python-jose/issues/398","tags":["issue-tracking","report"]},{"url":"https://github.com/mpdavis/python-jose/blob/3.5.0/jose/backends/native.py","tags":["technical-description","article","report"]},{"url":"https://github.com/mpdavis/python-jose/blob/3.5.0/jose/backends/cryptography_backend.py","tags":["technical-description","article","report"]},{"url":"https://www.vulncheck.com/advisories/python-jose-through-3.5.0-authentication-bypass-via-empty-hmac-key","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-120459","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-7jv8-hwmh-86qc"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/120xxx/CVE-2026-120459.json","tags":["advisory"]},{"url":"https://github.com/mpdavis/python-jose","tags":["package"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-120459","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-120459","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-120459","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-120459","title":"python-jose through 3.5.0 Authentication Bypass via Empty HMAC Key","description":"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.","status":"published","published":"2026-11-02T14:29:15.767Z","modified":"2026-11-09T14:01:34.817Z","cvss":[{"version":"4.0","score":9.1,"vector":"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","level":"critical","assessor":"cna"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-347"],"updated_at":"2026-11-09T15:33:44.265689Z"}],"euvd":[{"id":"EUVD-2026-115219","description":"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.","status":"published","published":"2026-11-02T14:29:15Z","modified":"2026-11-09T14:01:34Z","cvss":[{"version":"4.0","score":9.1,"vector":"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","level":"critical"}],"updated_at":"2026-11-09T15:17:13.549805Z"}],"ghsa":[{"id":"GHSA-7jv8-hwmh-86qc","title":"python-jose through 3.5.0 contains an authentication bypass vulnerability that allows...","description":"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.","status":"published","published":"2026-11-02T15:31:45Z","modified":"2026-11-02T15:31:46Z","cvss":[{"version":"4.0","score":9.1,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T18:00:16.184668Z"}],"nvd":[{"id":"CVE-2026-120459","description":"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.","status":"published","published":"2026-11-02T15:17:29.867Z","modified":"2026-11-09T14:17:06.93Z","cvss":[{"version":"4.0","score":9.1,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","assessor":"secondary"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-347"],"updated_at":"2026-11-09T16:14:54.431469Z"}],"osv":[{"id":"CVE-2026-120459","title":"python-jose through 3.5.0 Authentication Bypass via Empty HMAC Key","description":"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.","status":"published","published":"2026-11-02T14:29:15.767Z","modified":"2026-11-11T02:30:47.576268639Z","cvss":[{"version":"4.0","score":9.1,"vector":"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","level":"critical"}],"cwes":["CWE-347"],"updated_at":"2026-11-10T02:46:05.738924Z"},{"id":"DEBIAN-CVE-2026-120459","description":"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.","status":"published","published":"2026-11-02T15:17:29.867Z","modified":"2026-11-10T10:00:10.138775182Z","cvss":[{"version":"4.0","score":9.1,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"}],"updated_at":"2026-11-10T10:26:30.347596Z"},{"id":"UBUNTU-CVE-2026-120459","description":"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.","status":"published","published":"2026-11-02T15:17:00Z","modified":"2026-11-05T04:42:52Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"},{"version":"4.0","score":9.1,"vector":"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","level":"critical"}],"updated_at":"2026-11-05T13:33:25.727744Z"}]}}