Vulnerability in Apache Tomcat
CVE-2026-55276
Always-Incorrect Control Flow Implementation vulnerability in Apache Tomcat meant that special roles and empty authorisation constraints were not included when the effective web.xml was logged. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.0.M1 through 9.0.118, from 8.5.0 through 8.5.100. Other versions that have reached end of support may also be affected. Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119 which fixes the issue.
EPSS: 0.005 (42.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Apache Tomcat
- Apache Software Foundation Tomcat — versions 11.0.0-M1, 10.1.0-M1, 9.0.0.M1
Weakness classification (CWE)
References
- security@apache.org (vendor-advisory, Mailing List, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-55276?
- CVE-2026-55276 is a critical-severity vulnerability in Apache Tomcat, classified under Always-Incorrect Control Flow Implementation. CVSS score: 9.1/10. Published 2026-06-29.
- How severe is CVE-2026-55276?
- Critical severity. CVSS v3 base score is 9.1 out of 10.