Medium [CVE-2026-66299] Denial of Service via WebSocket chat example
This medium-severity Red Hat Linux advisory covers CVE-2026-66299 affecting Red Hat Hardened Images, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
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. This can lead to the affected system becoming unresponsive or crashing.
The impact is limited as the vulnerable component is part of an example application, which is generally not deployed in production environments. Exploitation requires the example application to be present and accessible.
Red Hat severity: Moderate — CVSS 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L). Weakness: CWE-770.
Affected Red Hat products: Red Hat Hardened Images; Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9. Red Hat fixing advisory: RHSA-2026:56039.
Affected products named by the advisory: Red Hat package: tomcat9; Red Hat package: pki-servlet-engine.
- 11.0.0
- 11.0.24
- 10.1.24
- 10.1.57
- 9.0.89
- 9.0.120
Official advisory · high-confidence parse· fetched 27 days ago·verify at source
- 11.0.25
- 10.1.58
- 9.0.121
- tomcat11-main-11.0.25-0.1.hum1
- RHSA-2026:56039
Official advisory · high-confidence parse· fetched 27 days ago·verify at source
Mitigation checklist
- To mitigate this vulnerability, remove the `examples` web application from your Apache Tomcat installation. This can typically be achieved by deleting the `examples` directory or `examples.war` file from the `webapps` directory of your Tomcat installation. A restart of the Tomcat service may be required for the changes to take full effect.
Official advisory · high-confidence parse· fetched 27 days ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.