Apache CXF before 3.3.4 and 3.2.11 provides all of the components that are required to build a fully fledged OpenId Connect service. There is a vulnerability in the access token services, where it does not validate that the authenticated principal is equal to that of the supplied clientId parameter in the request. If a malicious client was able to somehow steal an authorization code issued to another client, then they could exploit this vulnerability to obtain an access token for the other client.
Severity
CVSS 3.1
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
14% chance of exploitation in the next 30 days; higher than 96% of CVEs (scores of 2026-10-31)