Ubuntu USN · USN-8198-1

Tornado vulnerabilities

Published: Wed, 22 Apr 2026 17:52

CVE-2026-31958CVE-2026-35536

Summary

Several security issues were fixed in Tornado.

Details

It was discovered that Tornado incorrectly handled parsing of large multipart request bodies. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-31958) It was discovered that Tornado did not properly validate characters in cookie values. An attacker could possibly use this issue to inject arbitrary cookie attributes. (CVE-2026-35536)

Recommended actions per Ubuntu release

StackPatch playbook auto-generated per release codename and per affected package.

Ubuntu bionic

python-tornado→4.5.3-1ubuntu0.2+esm3apt_upgrade
Standard apt upgrade. Install 4.5.3-1ubuntu0.2+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python-tornado→4.5.3-1ubuntu0.2+esm3apt_upgrade
Standard apt upgrade. Install 4.5.3-1ubuntu0.2+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python-tornado-doc→4.5.3-1ubuntu0.2+esm3apt_upgrade
Standard apt upgrade. Install 4.5.3-1ubuntu0.2+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado-doc
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python3-tornado→4.5.3-1ubuntu0.2+esm3apt_upgrade
Standard apt upgrade. Install 4.5.3-1ubuntu0.2+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python3-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu focal

python-tornado→6.0.3+really5.1.1-3ubuntu0.1~esm5apt_upgrade_esm
Fixed at 6.0.3+really5.1.1-3ubuntu0.1~esm5 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado=6.0.3+really5.1.1-3ubuntu0.1~esm5
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
python-tornado-doc→6.0.3+really5.1.1-3ubuntu0.1~esm5apt_upgrade_esm
Fixed at 6.0.3+really5.1.1-3ubuntu0.1~esm5 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado-doc=6.0.3+really5.1.1-3ubuntu0.1~esm5
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
python3-tornado→6.0.3+really5.1.1-3ubuntu0.1~esm5apt_upgrade_esm
Fixed at 6.0.3+really5.1.1-3ubuntu0.1~esm5 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y python3-tornado=6.0.3+really5.1.1-3ubuntu0.1~esm5
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

Ubuntu jammy

python-tornado→6.1.0-3ubuntu0.1~esm5apt_upgrade_esm
Fixed at 6.1.0-3ubuntu0.1~esm5 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado=6.1.0-3ubuntu0.1~esm5
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
python-tornado-doc→6.1.0-3ubuntu0.1~esm5apt_upgrade_esm
Fixed at 6.1.0-3ubuntu0.1~esm5 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado-doc=6.1.0-3ubuntu0.1~esm5
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
python3-tornado→6.1.0-3ubuntu0.1~esm5apt_upgrade_esm
Fixed at 6.1.0-3ubuntu0.1~esm5 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y python3-tornado=6.1.0-3ubuntu0.1~esm5
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

Ubuntu noble

python-tornado→6.4.0-1ubuntu0.5apt_upgrade
Standard apt upgrade. Install 6.4.0-1ubuntu0.5 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python-tornado-doc→6.4.0-1ubuntu0.5apt_upgrade
Standard apt upgrade. Install 6.4.0-1ubuntu0.5 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado-doc
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python3-tornado→6.4.0-1ubuntu0.5apt_upgrade
Standard apt upgrade. Install 6.4.0-1ubuntu0.5 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python3-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu questing

python-tornado→6.4.2-3ubuntu0.3apt_upgrade
Standard apt upgrade. Install 6.4.2-3ubuntu0.3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python-tornado-doc→6.4.2-3ubuntu0.3apt_upgrade
Standard apt upgrade. Install 6.4.2-3ubuntu0.3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado-doc
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python3-tornado→6.4.2-3ubuntu0.3apt_upgrade
Standard apt upgrade. Install 6.4.2-3ubuntu0.3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python3-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu xenial

python-tornado→4.2.1-1ubuntu3.1+esm3apt_upgrade
Standard apt upgrade. Install 4.2.1-1ubuntu3.1+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python-tornado→4.2.1-1ubuntu3.1+esm3apt_upgrade
Standard apt upgrade. Install 4.2.1-1ubuntu3.1+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
python3-tornado→4.2.1-1ubuntu3.1+esm3apt_upgrade
Standard apt upgrade. Install 4.2.1-1ubuntu3.1+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y python3-tornado
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

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