CVE-2026-50631 json
Apache CXF: OAuth2: TOCTOU Race Condition in Refresh Token Processing
published 2026-06-12 4 mo ago modified 2026-11-05 4 d ago also GHSA-83r6-96m8-r52p , EUVD-2026-36399
- cvss
- 7.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 19%
- public exploits
- 0
- none known
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 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.
Patch / fix
- maven org.apache.cxf:cxf-rt-rs-security-oauth2 4.1.7, 4.2.2
- Apache Software Foundation Apache CXF 3.6.12, 4.1.7, 4.2.2
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 4 mo ago
Exploit prediction
0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 7.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
| CNA | 3.1 | 7.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
| GitHub | 3.1 | 7.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | org.apache.cxf:cxf-rt-rs-security-oauth2 | >=4.2.0, <4.2.2 <4.1.7 |
4.2.2 4.1.7 |
Affected products
- Apache Software Foundation Apache CXF
Classification
- Weakness
-
- CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
References
-
lists.apache.org
/thread/s83t3x4r626o9h8rt0ryr1w7w53l1vv8
vendor-advisory, web
-
openwall.com
/lists/oss-security/2026/06/11/8
web, mailing-list, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-50631
advisory
-
github.com
/apache/cxf
package
Sources
- CVE List CVE-2026-50631
- GitHub Advisory GHSA-83r6-96m8-r52p
- NVD CVE-2026-50631
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