Always-Incorrect Control Flow Implementation in Apache Tomcat - CVE-2026-55276
Published: June 30, 2026
Vulnerability identifier: #VU135864
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-55276
CWE-ID: CWE-670
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Apache Foundation
Affected software:
Apache Tomcat
Apache Tomcat
Detailed vulnerability description
The vulnerability allows a local user to obtain incomplete security configuration information.
The vulnerability exists due to logic errors in effective web.xml generation in the logged effective web.xml output when generating configuration logs. A local user can review the logged output to obtain incomplete security configuration information.
Special roles and empty authorization constraints are omitted from the logged effective web.xml.
How to mitigate CVE-2026-55276
Install security update from vendor's website.
Sources
- https://tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.1.56
- https://tomcat.apache.org/security-11.html#Fixed_in_Apache_Tomcat_11.0.23
- https://tomcat.apache.org/security-9.html#Fixed_in_Apache_Tomcat_9.0.119
- https://github.com/apache/tomcat/commit/25677f90fd721c26ef0f613d34ef8275b1aafc31