CVE-2026-32597

Summary

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 Software

VendorProductVersion RangeStatus
jpadillapyjwt< 2.12.0affected

Weaknesses

  • CWE-345: CWE-345: Insufficient Verification of Data Authenticity
  • CWE-863: CWE-863: Incorrect Authorization

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

CVE Program Container

Additional References

pyjwt: PyJWT accepts unknown crit header extensions (RFC 7515 §4.1.11 MUST violation)

Additional References

References