Is this vulnerability remotely exploitable?

Yes. Any external party that can supply JWTs to an application using the vulnerable PyJWT behavior could potentially exploit the issue by crafting tokens with unsupported critical extensions.

What access level does an attacker need?

The attacker only needs the ability to present or influence JWTs consumed by the application (for example, as a client controlling the Authorization header). No direct server or database access is required, though other weaknesses (like leaked signing keys) would amplify impact.

What is the safest general fix pattern?

Use JWT verification logic that strictly adheres to the JOSE/JWT specifications: validate all token headers, reject tokens that contain unknown or unsupported critical extensions, and default to a fail-closed behavior whenever header values are unexpected or non-standard.

Severity:

HIGH RISK

(7.5)

Improper Validation of JWT 'crit' Header (CWE-345) in PyJWT

CVE-2026-32597

Published:

Mar 13, 2026

Status:

Modified

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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May 6, 2026

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HIGH RISK

HIGH

(8.8)

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Privilege Escalation via Bypassed Access Control

May 6, 2026

Vulnerability Type

Category:

Improper Validation of Token Headers

CWE:

CWE-345;CWE-863

Impact:

Authentication and Authorization Bypass

Severity:

HIGH RISK

(7.5)

CVSS Version:

3.1

Vulnerability Type

Category:

Improper Validation of Token Headers

CWE:

CWE-345;CWE-863

Impact:

Authentication and Authorization Bypass

Severity:

HIGH RISK

(7.5)

CVSS Version:

3.1

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Improper Validation of JWT 'crit' Header (CWE-345) in PyJWT

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(8.6)

Server-Side Request Forgery (CWE-918) in OpenClaw Zalo Plugin sendPhoto

HIGH RISK

HIGH

(8.8)

Authorization Bypass (CWE-863) in OpenClaw Matrix Room Control Commands

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Ship clean & secure code faster

Ship clean & secure code faster

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