Is CVE-2026-102270 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-102270?

CVE-2026-102270 has a CVSS v3 severity of MEDIUM (4.4).

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CVE-2026-102270

Description

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.