CVE-2026-50631
Received Received - Intake
Race Condition in AbstractOAuthDataProvider Allows Token Reuse

Publication date: 2026-06-12

Last updated on: 2026-06-12

Assigner: Apache Software Foundation

Description
A race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypass single-use semantics and generate multiple valid Access Tokens, when 'recycleRefreshTokens' is set to false. A leaked refresh token can be replayed concurrently by multiple attackers or threads. Users are recommended to upgrade to versions 4.2.2 or 4.1.7, which fixes this issue.
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Meta Information
Published
2026-06-12
Last Modified
2026-06-12
Generated
2026-06-12
AI Q&A
2026-06-12
EPSS Evaluated
N/A
NVD
CVE-2026-50631
EUVD
EUVD-2026-36399
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
apache cxf to 4.2.2 (exc)
apache cxf to 4.1.7 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-367 The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
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Executive Summary

This vulnerability is a race condition in Apache CXF's OAuth2 implementation, specifically in the AbstractOAuthDataProvider component.

It occurs when concurrent requests use the same refresh token while the 'recycleRefreshTokens' setting is set to false, allowing these requests to bypass the intended single-use restriction on refresh tokens.

As a result, multiple valid access tokens can be generated from the same refresh token simultaneously.

Attackers who have obtained a leaked refresh token can exploit this by replaying it concurrently through multiple threads or requests.

The issue affects Apache CXF versions before 4.2.2 and before 4.1.7, and upgrading to these fixed versions is recommended.

Compliance Impact

The provided information does not specify how this vulnerability affects compliance with common standards and regulations such as GDPR or HIPAA.

Impact Analysis

This vulnerability can impact you by allowing attackers to generate multiple valid access tokens from a single leaked refresh token.

This undermines the security model that assumes refresh tokens are single-use, potentially leading to unauthorized access to protected resources.

If exploited, it could result in multiple attackers or processes gaining simultaneous access, increasing the risk of data breaches or unauthorized actions.

Mitigation Strategies

To mitigate this vulnerability, users are recommended to upgrade Apache CXF to versions 4.2.2 or 4.1.7, which contain fixes for this issue.

This upgrade prevents the race condition in AbstractOAuthDataProvider that allows concurrent requests using the same refresh token to bypass single-use semantics and generate multiple valid access tokens.

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