Auth bypass in Jpadilla Pyjwt

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.

EPSS: 0.003 (18.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-32597?
CVE-2026-32597 is a high-severity vulnerability in Jpadilla Pyjwt, classified under Insufficient Verification of Data Authenticity. CVSS score: 7.5/10. Published 2026-03-13.
How severe is CVE-2026-32597?
High severity. CVSS v3 base score is 7.5 out of 10.