{"id":"CVE-2026-102272","published":"2026-09-28T21:17:15.280","lastModified":"2026-09-29T15:17:17.323","description":"PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.prepare_key in jwt/algorithms.py is affected because raw-JWK detector does not normalize accepted Unicode byte-order marks before checking for JSON. This occurs when a public JWK is prefixed with a UTF-8 BOM and used in a mixed-algorithm verification path. As a result, public JWK bypasses asymmetric-key detection and becomes the HMAC secret. Consequently, an attacker who knows the public key can forge authenticated tokens. This issue is fixed in version 2.14.0.","cvssScore":7.4,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-347"],"vendors":[],"products":[],"references":[{"url":"https://github.com/jpadilla/pyjwt/commit/180783930de91876bc0d601f826a1f2956057291","tags":[]},{"url":"https://github.com/jpadilla/pyjwt/releases/tag/2.14.0","tags":[]},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-r6x4-923q-g947","tags":[]},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-r6x4-923q-g947","tags":[]}],"exploitRefs":[{"url":"https://github.com/jpadilla/pyjwt/commit/180783930de91876bc0d601f826a1f2956057291","tags":[]},{"url":"https://github.com/jpadilla/pyjwt/releases/tag/2.14.0","tags":[]},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-r6x4-923q-g947","tags":[]},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-r6x4-923q-g947","tags":[]}],"hasPoc":true,"ai":null}