CVE-2026-24880 Apache Tomcat - Request smuggling via invalid chunk extension
Severity: Low
Vendor: The Apache Software Foundation
Versions Affected:
Apache Tomcat 11.0.0-M1 to 11.0.18
Apache Tomcat 10.1.0-M1 to 10.1.52
Apache Tomcat 9.0.0.M1 to 9.0.115
Older, EOS versions may also be affected
Description:
Tomcat did not validate that contents of HTTP/1.1 chunk extensions. This
enabled a request smuggling attack if a reverse proxy in front of Tomcat
allowed CRLF sequences in an otherwise valid chunk extension.
Mitigation:
Users of the affected versions should apply one of the following
mitigations:
- Upgrade to Apache Tomcat 11.0.20 or later
- Upgrade to Apache Tomcat 10.1.53 or later
- Upgrade to Apache Tomcat 9.0.116 or later
Credit:
This issue was identified by Xclow3n
History:
2026-04-09 Original advisory
References:
[1] https://tomcat.apache.org/security-11.html
[2] https://tomcat.apache.org/security-10.html
[3] https://tomcat.apache.org/security-9.html
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