cyfenced.com →

[ CVE-2026-102270 · Published 28 Sep 2026 ]

PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.

CVSS 4.9 EPSS <1%1 agency advisoryFix available

[ Why it matters ]Priority signals

  • Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official 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.

[ Fixes ]Fixes and patches

  • pyjwt 2.14.0Fixed version · GitHub Advisories · pip package pyjwt: upgrade to 2.14.0 or later (affected <= 2.13.0)
  • Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
  • Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ Advisories ]Government CERT advisories

  • CERT-FRCERTFR-2026-AVI-1249

    Multiple vulnerabilities in VMware products Translated from French

    Multiple vulnerabilities have been discovered in VMware products. They allow an attacker to cause a security problem not specified by the vendor.

    CVE-2026-75595CVE-2026-53910CVE-2026-56404+288 more CVEs

[ Packages ]Affected open-source packages

[ References ]References