Auth bypass in Apache Cxf
CVE-2026-50623
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 or 3.6.12, which fixes this issue.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.005 (43.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 43.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.002
Affected products
- Apache Cxf
- Apache Software Foundation Cxf — versions 4.0.0, 0, 4.2.0
Weakness classification (CWE)
References
- lists.apache.org/thread/ydzj8m5mqmjy13xgyj9mkk9hfff63qq7 (vendor-advisory, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-50623?
- CVE-2026-50623 is a medium-severity vulnerability in Apache Cxf, classified under Improper Authentication. CVSS score: 4.8/10. Published 2026-06-12.
- How severe is CVE-2026-50623?
- Medium severity. CVSS v3 base score is 4.8 out of 10.