CVE-2026-32597

Description

PyJWT is a JSON Web Token implementation in Python. Prior to 2.12.0, PyJWT does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that PyJWT does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC. This vulnerability is fixed in 2.12.0.

PUBLISHED Reserved 2026-03-12 | Published 2026-03-12 | Updated 2026-03-13 | Assigner GitHub_M

Problem types

CWE-345: Insufficient Verification of Data Authenticity

CWE-863: Incorrect Authorization

Product status

References

github.com/.../pyjwt/security/advisories/GHSA-752w-5fwx-jx9f exploit

github.com/.../pyjwt/security/advisories/GHSA-752w-5fwx-jx9f

cve.org (CVE-2026-32597)

nvd.nist.gov (CVE-2026-32597)

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