CVE-2023-46589: Apache Tomcat

High severity, CVSS 7.5. EPSS: 2.7% chance of exploitation in the next 30 days.

Improper Input Validation vulnerability in Apache Tomcat.Tomcat from 11.0.0-M1 through 11.0.0-M10, from 10.1.0-M1 through 10.1.15, from 9.0.0-M1 through 9.0.82 and from 8.5.0 through 8.5.95 did not correctly parse HTTP trailer headers. A trailer header that exceeded the header size limit could cause Tomcat to treat a single request as multiple requests leading to the possibility of request smuggling when behind a reverse proxy. Older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.0-M11 onwards, 10.1.16 onwards, 9.0.83 onwards or 8.5.96 onwards, which fix the issue.

Affected products

• Apache Tomcat: from 8.5.0, before 8.5.96 (fixed in 8.5.96); from 9.0.0, before 9.0.83 (fixed in 9.0.83); from 10.1.0, before 10.1.16 (fixed in 10.1.16); version 11.0.0 only

Published 2023-11-28. Last modified 2026-06-17.