CVE-2026-55957: Apache Tomcat

High severity, CVSS 7.3. EPSS: 2.9% chance of exploitation in the next 30 days.

Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.

Affected products

• Apache Tomcat: before 9.0.101 (fixed in 9.0.101); from 10.1.0, before 10.1.37 (fixed in 10.1.37); from 11.0.0, before 11.0.5 (fixed in 11.0.5)

Published 2026-06-29. Last modified 2026-07-02.