CVE-2026-24733 Apache Tomcat - Security constraint bypass with HTTP/0.9
Severity: Low
Vendor: The Apache Software Foundation
Versions Affected:
Apache Tomcat 11.0.0-M1 to 11.0.14
Apache Tomcat 10.1.0-M1 to 10.1.49
Apache Tomcat 9.0.0.M1 to 9.0.112
Older, EOL versions are also be affected
Description:
Tomcat did not limit HTTP/0.9 requests to the GET method. If a security
constraint was configured to allow HEAD requests to a URI but deny GET
requests, the user could bypass that constraint on GET requests by
sending a (specification invalid) HEAD request using HTTP/0.9.
Mitigation:
Users of the affected versions should apply one of the following
mitigations:
- Upgrade to Apache Tomcat 11.0.15 or later
- Upgrade to Apache Tomcat 10.1.50 or later
- Upgrade to Apache Tomcat 9.0.113 or later
Credit:
This issue was identified by the Apache Tomcat security team
History:
2026-02-17 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
