CVE-2026-77791

Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack. This issue affects Apache Tomcat: from 11.0.0-M5 through 11.0.25, from 10.1.8 through 10.1.59, from 9.0.74 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.88 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

  • Published Sep 23, 2026
  • CVSS 7.5 high
  • 0.5% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

In the news

CVE-2026-77791 at the National Vulnerability Database