Is CVE-2026-77791 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-77791?

CVE-2026-77791 has a CVSS v3 severity of HIGH (7.5).

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CVE-2026-77791

Description

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.