CVE-2026-32597

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

Published Mar 12, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4564-1 pyjwt security update
Debian DSA Debian DSA DSA-6259-1 pyjwt security update
Github GHSA Github GHSA GHSA-752w-5fwx-jx9f PyJWT accepts unknown `crit` header extensions
Ubuntu USN Ubuntu USN USN-8133-1 PyJWT vulnerability
References
Link Providers
https://access.redhat.com/errata/RHSA-2026:10140 cve-icon
https://access.redhat.com/errata/RHSA-2026:10141 cve-icon
https://access.redhat.com/errata/RHSA-2026:10184 cve-icon
https://access.redhat.com/errata/RHSA-2026:12176 cve-icon
https://access.redhat.com/errata/RHSA-2026:13508 cve-icon
https://access.redhat.com/errata/RHSA-2026:13512 cve-icon
https://access.redhat.com/errata/RHSA-2026:13545 cve-icon
https://access.redhat.com/errata/RHSA-2026:13553 cve-icon
https://access.redhat.com/errata/RHSA-2026:13672 cve-icon
https://access.redhat.com/errata/RHSA-2026:13916 cve-icon
https://access.redhat.com/errata/RHSA-2026:17083 cve-icon
https://access.redhat.com/errata/RHSA-2026:19138 cve-icon
https://access.redhat.com/errata/RHSA-2026:19355 cve-icon
https://access.redhat.com/errata/RHSA-2026:19375 cve-icon
https://access.redhat.com/errata/RHSA-2026:19712 cve-icon
https://access.redhat.com/errata/RHSA-2026:21431 cve-icon
https://access.redhat.com/errata/RHSA-2026:21517 cve-icon
https://access.redhat.com/errata/RHSA-2026:22330 cve-icon
https://access.redhat.com/errata/RHSA-2026:24977 cve-icon
https://access.redhat.com/errata/RHSA-2026:26226 cve-icon
https://access.redhat.com/errata/RHSA-2026:37275 cve-icon
https://access.redhat.com/errata/RHSA-2026:42644 cve-icon
https://access.redhat.com/errata/RHSA-2026:6568 cve-icon
https://access.redhat.com/errata/RHSA-2026:6720 cve-icon
https://access.redhat.com/errata/RHSA-2026:6912 cve-icon
https://access.redhat.com/errata/RHSA-2026:6926 cve-icon
https://access.redhat.com/errata/RHSA-2026:8437 cve-icon
https://access.redhat.com/errata/RHSA-2026:8746 cve-icon
https://access.redhat.com/errata/RHSA-2026:8747 cve-icon
https://access.redhat.com/errata/RHSA-2026:8748 cve-icon
https://access.redhat.com/security/cve/CVE-2026-32597 cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2447194 cve-icon
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-752w-5fwx-jx9f cve-icon cve-icon cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2026/05/msg00008.html cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-32597 cve-icon
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32597.json cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-32597 cve-icon
History
Type Values Removed Values Added
First Time appeared Pyjwt Project
Pyjwt Project pyjwt
CPEs cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*
Vendors & Products Pyjwt Project
Pyjwt Project pyjwt
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Jpadilla
Jpadilla pyjwt
Vendors & Products Jpadilla
Jpadilla pyjwt
Type Values Removed Values Added
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.
Title PyJWT accepts unknown `crit` header extensions (RFC 7515 §4.1.11 MUST violation)
Weaknesses CWE-345
CWE-863
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 10, 2026, 12:05 PM
Reserved
Mar 12, 2026, 2:54 PM
Status
Modified
Published
Mar 13, 2026, 7:55 PM
Modified
Sep 10, 2026, 1:18 PM
Severity
Important
Public date
Mar 12, 2026, 9:41 PM