CVE-2026-32597

7.5

HIGH CVSS 3.1

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

Overview

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.

Details

INFO

Published Date :

March 13, 2026, 7:55 p.m.

Last Modified :

March 19, 2026, 1:30 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]

Impact

Affected Products

The following products are affected by CVE-2026-32597 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID	Vendor	Product	Action
1	Pyjwt_project	pyjwt

: Total Affected Vendor : 1 | Products : 1

Scoring

CVSS Scores

The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.

Score	Version	Severity	Vector	Exploitability Score	Impact Score	Source
	CVSS 3.1	HIGH				MITRE-CVE
	CVSS 3.1	HIGH				[email protected]

Solution

Update PyJWT to version 2.12.0 or later to properly validate critical header parameters.

Update PyJWT to version 2.12.0 or later.
Ensure library dependencies are up to date.

Public PoC/Exploit Available at Github

CVE-2026-32597 has a 4 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-32597.

URL	Resource
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-752w-5fwx-jx9f	Exploit Mitigation Vendor Advisory
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-752w-5fwx-jx9f	Exploit Mitigation Vendor Advisory

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-32597 is associated with the following CWEs:

CWE-345: Insufficient Verification of Data Authenticity

CWE-863: Incorrect Authorization

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-32597 weaknesses.

CAPEC-111: JSON Hijacking (aka JavaScript Hijacking) JSON Hijacking (aka JavaScript Hijacking) CAPEC-141: Cache Poisoning Cache Poisoning CAPEC-142: DNS Cache Poisoning DNS Cache Poisoning CAPEC-148: Content Spoofing Content Spoofing CAPEC-218: Spoofing of UDDI/ebXML Messages Spoofing of UDDI/ebXML Messages CAPEC-384: Application API Message Manipulation via Man-in-the-Middle Application API Message Manipulation via Man-in-the-Middle CAPEC-385: Transaction or Event Tampering via Application API Manipulation Transaction or Event Tampering via Application API Manipulation CAPEC-386: Application API Navigation Remapping Application API Navigation Remapping CAPEC-387: Navigation Remapping To Propagate Malicious Content Navigation Remapping To Propagate Malicious Content CAPEC-388: Application API Button Hijacking Application API Button Hijacking CAPEC-665: Exploitation of Thunderbolt Protection Flaws Exploitation of Thunderbolt Protection Flaws CAPEC-701: Browser in the Middle (BiTM) Browser in the Middle (BiTM)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

prefect421/mvidarr

MVidarr - The Music Video Management System

HTML Python Shell JavaScript CSS TypeScript Batchfile Dockerfile Mako Go Template

Updated: 2 weeks, 2 days ago

39 stars 1 fork 1 watcher

Born at : July 24, 2025, 1:49 a.m. This repo has been linked 2 different CVEs too.

researcherhojin/emelmujiro

Official website for Emelmujiro — AI education & consulting for enterprises

cloudflare-tunnel docker jwt nginx sqlite django react tailwindcss typescript vite

JavaScript Makefile Shell Dockerfile Python HTML CSS TypeScript

Updated: 2 weeks, 5 days ago

1 stars 0 fork 0 watcher

Born at : July 23, 2025, 9:25 a.m. This repo has been linked 2 different CVEs too.

runwhen-contrib/helm-charts

All Public RunWhen Helm Charts - Managed by terraform

Shell Dockerfile Go Template

Updated: 2 weeks, 3 days ago

1 stars 0 fork 0 watcher

Born at : Sept. 18, 2023, 10:09 a.m. This repo has been linked 94 different CVEs too.

jwpconsulting/projectify

Projectify, a free project management software

Python HTML Shell Nix JavaScript CSS Procfile

Updated: 6 days, 4 hours ago

14 stars 1 fork 1 watcher

Born at : Oct. 2, 2021, 6:54 a.m. This repo has been linked 1 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-32597 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-32597 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

Initial Analysis by [email protected]

Mar. 19, 2026

Action	Type	New Value
Added	CPE Configuration	OR cpe:2.3:a:pyjwt_project:pyjwt::::::::* versions up to (excluding) 2.12.0
Added	Reference Type	CISA-ADP: https://github.com/jpadilla/pyjwt/security/advisories/GHSA-752w-5fwx-jx9f Types: Exploit, Mitigation, Vendor Advisory
Added	Reference Type	GitHub, Inc.: https://github.com/jpadilla/pyjwt/security/advisories/GHSA-752w-5fwx-jx9f Types: Exploit, Mitigation, Vendor Advisory

New CVE Received by [email protected]

Mar. 13, 2026

Action	Type	New Value
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.
Added	CVSS V3.1	AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Added	CWE	CWE-345
Added	CWE	CWE-863
Added	Reference	https://github.com/jpadilla/pyjwt/security/advisories/GHSA-752w-5fwx-jx9f

CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0