CVE-2026-101918: Pyjwt Project Pyjwt

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a result, documented PyJWT exception handling does not contain the failure. Consequently, an unauthenticated request can raise an exception that may produce an HTTP 500 response. The advisory-defined affected implementation also includes jwt/api_jwt.py, verify_signature=False. This issue is fixed in version 2.15.0.

Affected products

• Pyjwt Project Pyjwt: from 2.0.0, before 2.15.0 (fixed in 2.15.0)

Published 2026-09-28. Last modified 2026-10-07.