---
id: CVE-2026-50631
title: >-
  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
summary: >-
  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…
severity: high
cvss: 7.4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-367
vendor: apache
product: cxf
affected:
  - cxf < 4.1.7
  - 'cxf >= 4.2.0, < 4.2.2'
patched:
  - cxf 4.2.2
published: '2026-06-12'
updated: '2026-08-07'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-50631'
references:
  - url: 'https://lists.apache.org/thread/s83t3x4r626o9h8rt0ryr1w7w53l1vv8'
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/06/11/8'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00393
epssPercentile: 0.30793
ingestedAt: '2026-08-07T14:14:17.479Z'
---

## Overview

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 or 3.6.12, which fixes this issue.

## Affected

- `cxf < 4.1.7`
- `cxf >= 4.2.0, < 4.2.2`

## Remediation

Upgrade past the affected range:

- `cxf 4.2.2`