CVE-2026-102269 — PyJWT: Non-canonical signature segments enable raw-token revocation bypass
PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT signature segment is affected because signature segment decoding accepts characters outside …
Published: 2026-09-28 · CVSS: 4.8 · CVSS 3.1
PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT signature segment is affected because signature segment decoding accepts characters outside the canonical Base64URL representation. This occurs when non-Base64URL characters are appended to a valid compact JWS signature segment. As a result, base64url_decode produces the same signature bytes for different serialized segments. Consequently, raw-token revocation checks can fail to recognize an equivalent modified token. This issue is fixed in version 2.14.0.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7