Vulnerability Details CVE-2026-102265
PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWS._load in jwt/api_jws.py is affected because parser catches ValueError but not RecursionError. This occurs when a deeply nested token header reaches json.loads. As a result, RecursionError escapes the documented PyJWT error hierarchy. Consequently, an unauthenticated malformed token can cause a request-level failure and HTTP 500. This issue is fixed in version 2.14.0.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 19.9%
CVSS Severity
CVSS v3 Score 5.3