Description
An authentication bypass vulnerability exists in the OAuth2 TokenIntrospectionService in Apache CXF. Due to a missing 'throw' keyword in the security context check, the introspection endpoint (/services/oauth2/introspect) can be accessed by any unauthenticated network attacker. However note that this is a safeguard only in the case that someone forgot to enable authentication on the service. Users are recommended to upgrade to version 4.2.2 or 4.1.7, which fixes this issue.
Problem types
CWE-287 Improper Authentication
Product status
4.2.0 (semver) before 4.2.2
Any version before 4.1.7
Credits
Guanping Zhang reported this vulnerability.
References
www.openwall.com/lists/oss-security/2026/06/11/3
lists.apache.org/thread/ydzj8m5mqmjy13xgyj9mkk9hfff63qq7