High · published September 23, 2026
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.39 through 9.0.121.
The following versions were EOL at the time the CVE was created but are
known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fix the issue.