CVE-2026-32597 — Insufficient Verification of Data Authenticity in Pyjwt

CWE-345 — Insufficient Verification of Data AuthenticityCWE-863 — Incorrect AuthorizationCWE-347 — Improper Verification of Cryptographic Signature9 documents8 sources
Severity
7.5HIGHNVD
EPSS
0.0%
top 98.94%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
3
Jpadilla PyjwtPyjwt Project PyjwtDebian Pyjwt
Timeline
PublishedMar 13
Latest updateMar 30

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NExploitability: 3.9 | Impact: 3.6

Affected Packages4 packages

▶CVEListV5jpadilla/pyjwt< 2.12.0
▶NVDpyjwt_project/pyjwt< 2.12.0
▶PyPIpyjwt_project/pyjwt< 2.12.0
▶debiandebian/pyjwt

🔴Vulnerability Details

3
GHSA
PyJWT accepts unknown `crit` header extensions↗2026-03-13
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OSV
CVE-2026-32597: PyJWT is a JSON Web Token implementation in Python↗2026-03-13
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OSV
PyJWT accepts unknown `crit` header extensions↗2026-03-13
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📋Vendor Advisories

3
Ubuntu
PyJWT vulnerability↗2026-03-30
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Red Hat
pyjwt: PyJWT accepts unknown `crit` header extensions (RFC 7515 §4.1.11 MUST violation)↗2026-03-12
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Debian
CVE-2026-32597: pyjwt - PyJWT is a JSON Web Token implementation in Python. Prior to 2.12.0, PyJWT does ...↗2026
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🕵️Threat Intelligence

1
Wiz
CVE-2026-32597 Impact, Exploitability, and Mitigation Steps | Wiz↗
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💬Community

1
Bugzilla
CVE-2026-32597 pyjwt: PyJWT accepts unknown `crit` header extensions (RFC 7515 §4.1.11 MUST violation)↗2026-03-12
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