Vulnerability details
CVE-2026-66299
Apache Software Foundation Apache Tomcat
Apache Tomcat: DoS via WebSocket chat example
CVSS 3.1
7.5High
Official 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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.5High | 3.1 | CISA ADP / Vulnrichment (CISA-ADP) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Apache Software Foundation | Apache Tomcat | 10.1.24 ≤ v ≤ 10.1.57 | CVEProject cvelistV5 (CNA) |
| Apache Software Foundation | Apache Tomcat | 11.0.0-M20 ≤ v ≤ 11.0.24 | CVEProject cvelistV5 (CNA) |
| Apache Software Foundation | Apache Tomcat | 9.0.89 ≤ v ≤ 9.0.120 | CVEProject cvelistV5 (CNA) |
References and advisories
2
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Details
- Published
- 2026-07-28
- Last updated
- 2026-07-28
- State
- Published
- Assigner (CNA)
- apache
Exploit prediction (EPSS)
0.55%
Probability of exploitation in 30 days
46.3%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-400Uncontrolled Resource Consumption