python-tornado: Ubuntu package security update (USN-8952-1)

python-tornado. An Ubuntu security notice lists distribution packages to check. Match your Ubuntu release and installed package version to Canonical’s fixed versions.

CyberLens Lab•Site publication: 22 Oct 2026•3 min read

What this update means

Ubuntu security notices describe fixes supplied through Ubuntu packages. Start with your Ubuntu release and the package actually installed. Ubuntu can backport a security patch while retaining an older upstream version number. The distribution package revision therefore matters: a lower-looking upstream version does not, by itself, show that a package is still vulnerable. A package advisory is not evidence of a breach.

What the source confirms

The Ubuntu security notice describes the issue (brief excerpt):

Tornado could be made to crash or expose sensitive information if it received specially crafted network traffic.

Reference: USN-8952-1.
Product: python-tornado.
Publisher or vendor: Canonical.
Reported severity: not supplied in this record.
CVE identifiers: CVE-2023-54397, CVE-2024-14029, CVE-2026-103262, CVE-2026-103263, CVE-2026-91990, CVE-2026-91992.
Source publication date: 22 October 2026.
Exploitation: not established by this record.

Affected products or versions

Ubuntu 18.04 ESM (bionic)
Ubuntu 20.04 ESM (focal)
Ubuntu 22.04 LTS (jammy)
Ubuntu 24.04 LTS (noble)
Ubuntu 26.04 LTS (resolute)
Ubuntu 26.10 (stonking)

Check the official source for its complete product list.

Fixed versions or packages

Ubuntu 18.04 ESM (bionic): python-tornado 4.5.3-1ubuntu0.2+esm4
Ubuntu 20.04 ESM (focal): python-tornado 6.0.3+really5.1.1-3ubuntu0.1~esm7
Ubuntu 22.04 LTS (jammy): python-tornado 6.1.0-3ubuntu0.1~esm6
Ubuntu 24.04 LTS (noble): python-tornado 6.4.0-1ubuntu0.6
Ubuntu 26.04 LTS (resolute): python-tornado 6.5.4-0.1ubuntu0.2
Ubuntu 26.10 (stonking): python-tornado 6.5.5-5ubuntu1.1

Check the official source for its complete product list.

What to do next

Match the release codename and package name to the entries above. Use your configured Ubuntu update channel and Canonical’s instructions for that release, including any service restart or reboot requirements. Check whether the package belongs to standard support or an extended maintenance service. Record the installed revision after updating and verify that the application still works.

A small, read-only check

Inspect your release and installed package inventory:

lsb_release -ds
dpkg-query -W

These commands only display local information. Find the relevant package in the output and compare its complete version, including the Ubuntu revision, with the notice.

Prevention and recovery

Keep an inventory of software and its owner, retain tested backups, and review update notifications. After an approved update, check the running service and normal application behaviour. If you find signs of unauthorized access, preserve logs and involve your incident-response contact; installing a patch alone does not remove an existing intrusion.

Official source

Read the official advisory. Check it for later corrections, complete product lists and deployment instructions. This briefing explains the supplied evidence; it does not diagnose the security of any particular device.