CVE-2026-50623 Apache CXF: Authentication Bypass in OAuth2 TokenIntrospectionService
Unauthenticated attackers can access the OAuth2 token introspection endpoint if service authentication is not explicitly enabled, bypassing security controls.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-50623?
CVE-2026-50623 is a medium-severity authentication bypass vulnerability in Apache Cxf, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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 or 3.6.12, which fixes this issue.
Weakness: CWE-287
Which versions are affected by CVE-2026-50623?
4 open source packages ship an affected version, including org.apache.cxf:cxf-rt-rs-security-oauth2. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.apache.cxf:cxf-rt-rs-security-oauth2 Maven | All versions | 4.1.7 |
org.apache.cxf:cxf-rt-rs-security-oauth2 Maven | All versions | 4.1.7 |
org.apache.cxf:cxf-rt-rs-security-oauth2 Maven | From 4.2.0 | 4.2.2 |
org.apache.cxf:cxf-rt-rs-security-oauth2 Maven | From 4.2.0 | 4.2.2 |
Products include Apache Cxf.
How do I fix CVE-2026-50623?
Upgrade org.apache.cxf:cxf-rt-rs-security-oauth2 to a fixed version for your release line: 4.1.7 or 4.2.2.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-50623 being exploited?
There is no known exploitation of CVE-2026-50623 in the wild and no public exploit code.
Other vulnerabilities in Apache Cxf
- CVE-2012-2379 XML Signature/Encryption Not Validated in Apache CXF
- CVE-2026-66909 Apache CXF: Unsafe deserialization of inbound JMS ObjectMessage
- CVE-2026-68079 Apache CXF: DefaultEncryptingCodeDataProvider allows unlimited authorization code replay
- CVE-2026-50628 Apache CXF: OAuth2: Inverted IP Binding Check Defeats Security Control
- CVE-2025-48913 Apache CXF: Untrusted JMS configuration can lead to RCE
Sources
Also known as GHSA-542g-m3fx-q86f.