CVE-2026-102270: Pyjwt Project Pyjwt

Medium severity, CVSS 4.9. EPSS: 0.2% chance of exploitation in the next 30 days.

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT is_pem_format is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, is_pem_format performs unbounded backtracking while searching for a PEM end marker. Consequently, an attacker can cause intensive CPU consumption. This issue is fixed in version 2.14.0.

Affected products

Published 2026-09-28. Last modified 2026-10-06.