CVE-2023-34981: Apache Tomcat

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

A regression in the fix for bug 66512 in Apache Tomcat 11.0.0-M5, 10.1.8, 9.0.74 and 8.5.88 meant that, if a response did not include any HTTP headers no AJP SEND_HEADERS messare woudl be sent for the response which in turn meant that at least one AJP proxy (mod_proxy_ajp) would use the response headers from the previous request leading to an information leak.

Affected products

• Apache Tomcat: version 8.5.88 only; version 9.0.74 only; version 10.1.8 only; version 11.0.0 only

Published 2023-06-21. Last modified 2026-06-17.