Riskcovery

CVE-2026-32597

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

State
Published
Severity
7.5 High
Published
Mar 12, 2026
Updated
Sep 10, 2026
Reserved
Mar 12, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NGitHub_M
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nredhat-SADP

Weaknesses

  • CWE-345 Insufficient Verification of Data Authenticity
  • CWE-863 Incorrect Authorization
  • CWE-347 Improper Verification of Cryptographic Signature

Affected Products

ProductVersions
pyjwtjpadilla
  • < 2.12.0Affected

References

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