CVE-2026-55956: Apache Tomcat: Security constraints for default servlet ignored method

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-29 · updated 2026-10-25
Weakness: CWE-285

Description

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.

Affected products

Apache Tomcat: before 9.0.119; from 10.1.0 before 10.1.56; from 11.0.0 before 11.0.23 — fixed in 9.0.119, 10.1.56, 11.0.23

How to fix

Upgrade to a fixed version: Apache Tomcat 9.0.119, 10.1.56, 11.0.23. Check the vendor advisory for mitigations.

References

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