Executive brief
Apache Tomcat is a widely-used application server that handles user authentication for web applications. A flaw in its authentication mechanism allows users to gain access even if they don't actually exist in the system's user database, under specific authentication methods like client certificates or SPNEGO. This creates an unauthorized access risk and could enable attackers to bypass security controls designed to restrict who can use the application.
Technical details
An improper authentication vulnerability in Apache Tomcat's DataSourceRealm component allows a user to be authenticated even when the user does not exist in the realm's database. This occurs specifically when using alternative authentication mechanisms such as CLIENT-CERT or SPNEGO. The vulnerability represents a "fail open" condition where principal lookup fails to properly validate user existence. Affected versions include Tomcat 11.0.0-M1 through 11.0.24, 10.1.0-M1 through 10.1.57, 9.0.0.M1 through 9.0.120, and older EOL versions 8.5.0 through 8.5.100 and 7.0.0 through 7.0.109. Patches are available in versions 11.0.25, 10.1.58, and 9.0.121.
Affected products
- Apache Tomcat 11.0.0-M1 through 11.0.24, 10.1.0-M1 through 10.1.57, 9.0.0.M1 through 9.0.120, 8.5.0 through 8.5.100, 7.0.0 through 7.0.109
Timeline
- 2026-08-25: disclosed: CVE-2026-68569 published