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High 7.5Published Jul 28, 2026

CVE-2026-66299Apache Tomcat: DoS via WebSocket chat example

Updated under an hour ago ()

Does this affect you?

It affects Apache Software Foundation Apache Tomcat and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-400
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
apache
NVD analysis
Analyzed
Record last updated
Jul 28, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Apache Software Foundation Apache Tomcat
apache_software_foundation:apache_tomcat (from the name)
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; through 8.5.100 not affected
CNA record
apache tomcat
apache:tomcat
from 9.0.89 before 9.0.121; from 10.1.24 before 10.1.58; from 11.0.1 before 11.0.25; 11.0.0; 11.0.0; 11.0.0; 11.0.0; 11.0.0; and 2 more ranges
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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