CVE-2026-32597
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:Mar 12, 2026
Last Modified:May 5, 2026
EPS:Mar 12, 2026
EPSS Score:0.00013
CVSS Score:7.5
Affected Products
Vendor
Product
Action
Vendor
Jpadilla
Product
Pyjwt
Jpadilla
Pyjwt
Vendor
Pyjwt Project
Product
Pyjwt
Pyjwt Project
Pyjwt
Exploits
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
References
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
