CVE-2026-91990

NameCVE-2026-91990
DescriptionTornado before 6.5.8 contains a memory amplification vulnerability in parse_multipart_form_data that splits multipart data before validating the max_parts limit. Attackers can send crafted multipart requests with many parts to create large transient lists, exhausting server memory and causing denial of service.
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 Bugs1148323

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
python-tornado (PTS)bookworm, bookworm (security)6.2.0-3+deb12u4vulnerable
trixie (security), trixie6.4.2-3+deb13u2vulnerable
forky, sid6.5.5-5vulnerable

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
python-tornadosource(unstable)(unfixed)1148323

Notes

[trixie] - python-tornado <no-dsa> (Minor issue)
https://github.com/tornadoweb/tornado/security/advisories/GHSA-8423-8fgw-73vq
Search for package or bug name: Reporting problems