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[ CVE-2026-102269 · Published 28 Sep 2026 ]

PyJWT: Non-canonical signature segments enable raw-token revocation bypass

CVSS 5.4 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 signature segment is affected because signature segment decoding accepts characters outside the canonical Base64URL representation. This occurs when non-Base64URL characters are appended to a valid compact JWS signature segment. As a result, base64url_decode produces the same signature bytes for different serialized segments. Consequently, raw-token revocation checks can fail to recognize an equivalent modified token. 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

[ 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