CVE-2026-32597

PyJWT prior to 2.12.0 does not validate the crit header (RFC 7515 §4.1.11). If a JWS contains a crit array with extensions PyJWT cannot understand, the library accepts the token instead of rejecting it, violating the MUST requirement. This CVE affects PyJWT and is fixed in version 2.12.0. Remedia...

CVE-2026-48526

PyJWT (Python) prior to 2.13.0 did not validate the use of JSON Web Keys in HMAC verification, allowing an attacker to use the issuer public key as the HMAC secret during token verification. This could enable forging tokens when mixing RS/EC/JWK and HS algorithms. The issue is fixed in PyJWT 2.13...

CVE-2026-48522

PyJWKClient in PyJWT prior to 2.13.0 passes its uri argument directly to urllib.request.urlopen(), allowing attacker-controlled jku URLs to trigger SSRF and related token-forgery scenarios via file://, ftp://, or data: schemes. Affected component: PyJWKClient (Python). Root cause: lack of a schem...

CVE-2026-48524

CVE-2026-48524 affects PyJWT prior to 2.13.0. The issue is in PyJWKClient.get_signing_key(), which can force a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since the kid is from an unverified token header, an attacker can trigger unlimite...