Apache CXF up to 4.1.6/4.2.1 OAuth2 TokentrospectionService improper authentication

Summaryinfo

A vulnerability marked as critical has been reported in Apache CXF up to 4.1.6/4.2.1. The impacted element is the function TokentrospectionService of the component OAuth2. This manipulation causes improper authentication. This vulnerability is registered as CVE-2026-50623. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Apache CXF up to 4.1.6/4.2.1. It has been declared as critical. Affected by this vulnerability is the function TokentrospectionService of the component OAuth2. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at lists.apache.org. This vulnerability is known as CVE-2026-50623. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/17/2026).

Upgrading to version 4.1.7 or 4.2.2 eliminates this vulnerability.

The vulnerability is also documented in the databases at EUVD (EUVD-2026-36393) and CERT Bund (WID-SEC-2026-1895). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Apache CXF

Productinfo

Type

• Application Server Software

Vendor

• Apache

Name

• CXF

Version

• 4.1.0
• 4.1.1
• 4.1.2
• 4.1.3
• 4.1.4
• 4.1.5
• 4.1.6
• 4.2.0
• 4.2.1

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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