CVE-2026-66299

Apache Tomcat: DoS via WebSocket chat example

State: Published
Severity: 7.5 High
Published: Jul 28, 2026
Updated: Jul 28, 2026
Reserved: Jul 24, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	CISA-ADP

Weaknesses

CWE-400 Uncontrolled Resource Consumption

Affected Products

Product	Versions
Apache TomcatApache Software Foundation	11.0.0-M20 through 11.0.24Affected 10.1.24 through 10.1.57Affected 9.0.89 through 9.0.120Affected 8.5.100 and earlierNot affected

References

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