CVE-2026-102270

Published: Sep 28, 2026Modified: Oct 6, 2026

4.9

Vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Exploitability: 1.2 / Impact: 3.6

Source: NVD

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.

Affected (1)

Products: Pyjwt Project: Pyjwt

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Pyjwt Project Pyjwt	version < 2.14.0

Related CWEs

Inefficient Regular Expression Complexity

The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.

References (4)

https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07

Source: security-advisories@github.com

Patch

https://github.com/jpadilla/pyjwt/releases/tag/2.14.0

Source: security-advisories@github.com

ProductRelease Notes

https://github.com/jpadilla/pyjwt/security/advisories/GHSA-jwrc-g2q2-pq5p

Source: security-advisories@github.com

ExploitPatchVendor Advisory

https://github.com/jpadilla/pyjwt/security/advisories/GHSA-jwrc-g2q2-pq5p

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

ExploitPatchVendor Advisory

Timeline

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