CVE-2026-77791

NameCVE-2026-77791
DescriptionUncontrolled 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1148824

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
tomcat10 (PTS)bookworm, bookworm (security)10.1.55-1~deb12u1vulnerable
trixie (security), trixie10.1.55-1~deb13u1vulnerable
forky, sid10.1.60-1fixed
tomcat11 (PTS)trixie (security), trixie11.0.22-1~deb13u1vulnerable
forky, sid11.0.24-1vulnerable
tomcat9 (PTS)bookworm9.0.70-2fixed
trixie9.0.95-1fixed
forky, sid9.0.122-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
tomcat10source(unstable)10.1.60-1
tomcat11source(unstable)(unfixed)1148824
tomcat9source(unstable)9.0.70-2

Notes

Starting with 9.0.70-2 src:tomcat9 no longer ships the server stack, using that as the fixed version
https://github.com/apache/tomcat/commit/ce291bbc65393e3bfbec2a8d23fcee0106a1ade9 (11.0.26)
https://github.com/apache/tomcat/commit/e896f73c868f66dfb2a93565fda4d13cd5909d2d (10.1.60)
https://github.com/apache/tomcat/commit/7a5945f1de1d3310214234dfbbd7c569af52d058 (9.0.122)

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