Ubuntu USN · USN-8450-1

Tomcat vulnerabilities

Published: Thu, 18 Jun 2026 15:56

CVE-2026-42498CVE-2026-41293CVE-2026-43515CVE-2026-41284

Summary

Several security issues were fixed in Tomcat.

Details

It was discovered that Tomcat did not properly limit the size of WebDAV LOCK and PROPFIND request bodies. A remote attacker could possibly use this issue to cause Tomcat to consume excessive memory, resulting in a denial of service. (CVE-2026-41284) It was discovered that Tomcat incorrectly validated HTTP/2 header fields. A remote attacker could use this issue to cause Tomcat to crash or possibly execute arbitrary code. (CVE-2026-41293) It was discovered that Tomcat did not properly clear HTTP authentication headers during WebSocket connection upgrades and redirects. A remote attacker could possibly use this issue to obtain sensitive credentials. (CVE-2026-42498) It was discovered that Tomcat incorrectly handled authorization when multiple method constraints defined the same HTTP method. A remote attacker could possibly use this issue to bypass authorization restrictions. (CVE-2026-43515)

Recommended actions per Ubuntu release

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

Ubuntu resolute

tomcat11→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 tomcat11=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libtomcat11-embed-java→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 libtomcat11-embed-java=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libtomcat11-java→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 libtomcat11-java=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
tomcat11→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 tomcat11=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
tomcat11-admin→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 tomcat11-admin=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
tomcat11-common→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 tomcat11-common=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
tomcat11-docs→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 tomcat11-docs=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
tomcat11-examples→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 tomcat11-examples=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
tomcat11-user→11.0.18-1ubuntu0.1~esm1apt_upgrade_esm
Fixed at 11.0.18-1ubuntu0.1~esm1 — 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 tomcat11-user=11.0.18-1ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

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