CVE-2026-66299
Medium
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.
SeverityMedium
CVSS5.3
Exploit probability—
Product
Apache Tomcat
PublishedJul 28, 2026
First seenJul 28, 2026
Weakness typeCWE-400Uncontrolled resource consumption
How to fix
Update
- apache tomcat9.0.121, 10.1.58, 11.0.25 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| apache tomcat | 9.0.89 ≤ v < 9.0.121, 10.1.24 ≤ v < 10.1.58, 11.0.1 ≤ v < 11.0.25, 11.0.0 | 9.0.121, 10.1.58, 11.0.25 |
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