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CVE-2026-32597

PyJWT accepts unknown `crit` header extensions (RFC 7515 §4.1.11 MUST violation) PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
jpadilla / pyjwtaffected < 2.12.0

CWE

CWE-345, CWE-863

References

ADP enrichment

CISA-ADP

No English description supplied.

CVE

No English description supplied.

redhat-SADP

A missing verification step has been discovered in PyJWT. 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.