CVE-2026-66299

HIGH

Apache Tomcat: DoS via WebSocket chat example

Title source: cna
STIX 2.1

Description

Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example. This issue affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through 9.0.120. Users who have followed the security guidance to remove the examples web application are not affected by this issue. Users are recommended to remove the examples web application or to upgrade to version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue.

References (2)

Core 2

Scores

CVSS v3 7.5
EPSS 0.0031
EPSS Percentile 23.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-400
Status published
Products (4)
Apache Software Foundation/Apache Tomcat < 8.5.100
Apache Software Foundation/Apache Tomcat 10.1.24 - 10.1.57
Apache Software Foundation/Apache Tomcat 11.0.0-M20 - 11.0.24
Apache Software Foundation/Apache Tomcat 9.0.89 - 9.0.120
Published Jul 28, 2026
Tracked Since Jul 28, 2026