CVE-2026-24880: Apache Tomcat: Request smuggling via invalid chunk extension

[Mark Thomas <markt () apache org>]

Severity: low

Affected versions:

- Apache Tomcat 11.0.0-M1 through 11.0.18
- Apache Tomcat 10.1.0-M1 through 10.1.52
- Apache Tomcat 9.0.0.M1 through 9.0.115
- Apache Tomcat 8.5.0 through 8.5.100
- Apache Tomcat 7.0.0 through 7.0.109
- Apache Tomcat before 7.0.0 unknown
- Apache Tomcat 8.0.0-RC1 through 8.0.53 unknown

Description:

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response 
Smuggling') vulnerability in Apache Tomcat via invalid chunk extension.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.18, from 
10.1.0-M1 through 10.1.52, from 9.0.0.M1 through 9.0.115, from 8.5.0 
through 8.5.100, from 7.0.0 through 7.0.109.
Other, unsupported versions may also be affected.

Users are recommended to upgrade to version 11.0.20, 10.1.52 or 9.0.116, 
which fix the issue.

Credit:

Xclow3n (finder)

References:

https://lists.apache.org/thread/2c682qnlg2tv4o5knlggqbl9yc2gb5sn
https://tomcat.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-24880