CVE-2026-57818: Apache CXF: OAuth2 Authorization Code Replay via TOCTOU in JCacheCodeDataProvider

[Colm O hEigeartaigh <coheigea () apache org>]

Severity: low 

Affected versions:

- Apache CXF (org.apache.cxf:cxf-rt-rs-security-oauth2) 4.2.0 before 4.2.3
- Apache CXF (org.apache.cxf:cxf-rt-rs-security-oauth2) 4.0.0 before 4.1.8
- Apache CXF (org.apache.cxf:cxf-rt-rs-security-oauth2) before 3.6.12

Description:

A race condition in JCacheCodeDataProvider allows an attacker to redeem a single authorization code multiple times via 
concurrent requests, resulting in the issuance of multiple distinct, valid access tokens. Users are recommended to 
upgrade to versions 4.2.3, 4.1.8 or 3.6.12, which fix this issue.

Credit:

Guanping Zhang reported this vulnerability (finder)

References:

https://cxf.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-57818