Auth bypass in Apache Tomcat
CVE-2026-55956
Improper Authorization vulnerability in Apache Tomcat leads to security constraints specified for the default servlet ignoring any method or method omission configured as part of the constraint. 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, from 7.0.0 through 7.0.109. 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 fix the issue.
EPSS: 0.015 (72.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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-2026-55956?
- CVE-2026-55956 is a medium-severity vulnerability in Apache Tomcat, classified under Improper Authorization. CVSS score: 6.5/10. Published 2026-06-29.
- How severe is CVE-2026-55956?
- Medium severity. CVSS v3 base score is 6.5 out of 10.