jpadilla pyjwt up to 2.12.x JWKS Endpoint PyJWKClient.get_signing_key cleanup

Summaryinfo

A vulnerability classified as problematic was found in jpadilla pyjwt up to 2.12.x. Affected is the function PyJWKClient.get_signing_key of the component JWKS Endpoint. Executing a manipulation can lead to cleanup. This vulnerability is tracked as CVE-2026-48524. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in jpadilla pyjwt up to 2.12.x and classified as problematic. This vulnerability affects the function PyJWKClient.get_signing_key of the component JWKS Endpoint. The manipulation with an unknown input leads to a cleanup vulnerability. The CWE definition for the vulnerability is CWE-460. The product does not clean up its state or incorrectly cleans up its state when an exception is thrown, leading to unexpected state or control flow. As an impact it is known to affect availability. CVE summarizes:

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.get_signing_key() forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited outbound requests. The vulnerability surfaces only when a JWKS fetch fails; an attacker can attempt to provoke that with sustained unknown-kid traffic, but the outcome depends on upstream JWKS-endpoint behavior (rate limiting, transient errors) which is beyond the attacker's control. This vulnerability is fixed in 2.13.0.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-48524 since 05/21/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

Upgrading to version 2.13.0 eliminates this vulnerability.

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Productinfo

Vendor

• jpadilla

Name

• pyjwt

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12

Website

• Product: https://github.com/jpadilla/pyjwt/

CPE 2.3info

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CPE 2.2info

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