CVE-2026-50629: Apache CXF: OAuth2: Log Injection via Unsanitized Client Identifier

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

Severity: low 

Affected versions:

- Apache CXF (org.apache.cxf:cxf-rt-rs-security-oauth2) 4.2.0 before 4.2.2
- Apache CXF (org.apache.cxf:cxf-rt-rs-security-oauth2) before 4.1.7

Description:

The 'clientId' parameter from incoming HTTP requests is directly concatenated into OAuth2 server log warning messages 
without sanitizing control characters. This allows an attacker to inject arbitrary content, including fake log entries, 
into the server's log files. Users are recommended to upgrade to versions 4.2.2 or 4.1.7, which fixes this issue.

Credit:

Guanping Zhang reported this vulnerability. (finder)

References:

https://cxf.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-50629