CVE-2026-50631: Apache CXF · Time-of-check Time-of-use (TOCTOU) Race Condition
Affects Apache CXFSource CVE Database V5
Not known to be exploited · CVSS 7.4 High · fixed in 4.2.2 : patch Apache CXF soon.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.2.2, 4.1.7, 3.6.12
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 12 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade Apache to 4.2.2, 4.1.7 or 3.6.12.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Apache Software FoundationApache CXF | Affected
| Fixed in
|
| Apache Software FoundationApache CXF | Affected
| Fixed in
|
| Apache Software FoundationApache CXF | Affected
| Fixed in
|
MavenApache Software Foundation/org.apache.cxf:cxf-rt-rs-security-oauth2pkg:maven/Apache Software Foundation/org.apache.cxf:cxf-rt-rs-security-oauth2Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users are strongly advised to upgrade Apache CXF to versions 4.2.2, 4.1.7, or 3.6.12 where this vulnerability is fixed. No other official remediation or temporary fixes are indicated. Patch status is confirmed by the vendor advisory stating fixed versions. Until upgraded, avoid configurations with 'recycleRefreshTokens' set to false if possible.
Description
CVE-2026-50631 is a high-severity race condition vulnerability in Apache CXF's AbstractOAuthDataProvider. It allows concurrent requests using the same refresh token to bypass single-use restrictions and generate multiple valid access tokens when 'recycleRefreshTokens' is set to false. This flaw can enable attackers to replay a leaked refresh token concurrently, potentially compromising access control. Fixed versions include 4.2.2, 4.1.7, and 3.6.12.