CVE-2025-55668: Apache Tomcat: session fixation via rewrite valve

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-13 · updated 2026-06-17
Weakness: CWE-384

Description

Session Fixation vulnerability in Apache Tomcat via rewrite valve. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.7, from 10.1.0-M1 through 10.1.41, from 9.0.0.M1 through 9.0.105. Older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.8, 10.1.42 or 9.0.106, which fix the issue.

Affected products

Apache Tomcat: from 9.0.1 before 9.0.106; from 10.0.0 before 10.1.42; from 11.0.0 before 11.0.8; 9.0.0-milestone1, 9.0.0-milestone10, 9.0.0-milestone11, 9.0.0-milestone12, 9.0.0-milestone13, 9.0.0-milestone14 (+21) — fixed in 10.1.42, 11.0.8, 9.0.106

How to fix

Upgrade to a fixed version: Apache Tomcat 10.1.42, 11.0.8, 9.0.106. Check the vendor advisory for mitigations.

References

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