Executive brief
Apache Tomcat is a widely-used application server that hosts Java web applications. A flaw in how Tomcat processes security role definitions allows attackers to bypass authorization controls by exploiting role references that are incorrectly treated as role aliases. This could enable unauthorized users to access protected resources or perform restricted actions within web applications running on affected servers.
Technical details
The vulnerability is an improper authorization issue in Apache Tomcat's Realm component, where security-role-ref definitions are incorrectly used as role aliases in addition to their correct usage with Request.isUserInRole(). This causes role-based access control (RBAC) checks to be bypassed when declarative role constraints are in place. The attack requires network access to a Tomcat instance hosting a vulnerable application, but does not require authentication or user interaction to exploit. An attacker can craft requests that exploit the mishandled role aliases to gain unauthorized access to protected servlets or resources. Fixes are available in Apache Tomcat 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, 9.0.25 through 9.0.120, 8.5.46 through 8.5.100, 7.0.97 through 7.0.109
Timeline
- 2026-08-25: disclosed
- 2026-08-25: patched: Fixes released in versions 11.0.25, 10.1.58, and 9.0.121