USN-8417-1: Tomcat vulnerabilities

Publication date

10 June 2026

Overview

Several security issues were fixed in Tomcat.


Packages

Details

It was discovered that Tomcat did not properly limit the size of
WebDAV LOCK and PROPFIND request bodies. A remote attacker could
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 use this issue to obtain
sensitive credentials. (CVE-2026-42498)

It was discovered that Tomcat incorrectly handled digest
authentication. A remote attacker could possibly use this issue to
bypass authentication restrictions....

It was discovered that Tomcat did not properly limit the size of
WebDAV LOCK and PROPFIND request bodies. A remote attacker could
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 use this issue to obtain
sensitive credentials. (CVE-2026-42498)

It was discovered that Tomcat incorrectly handled digest
authentication. A remote attacker could possibly use this issue to
bypass authentication restrictions. (CVE-2026-43512)

It was discovered that Tomcat incorrectly handled case sensitivity
in LockOutRealm. A remote attacker could possibly use this issue to
bypass account lockout protections and obtain sensitive information.
(CVE-2026-43513)

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)


Update instructions

After a standard system update you need to restart Tomcat to make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
26.04 LTS resolute libtomcat10-embed-java –  10.1.40-1ubuntu1.26.04.1
libtomcat10-java –  10.1.40-1ubuntu1.26.04.1
libtomcat9-java –  9.0.115-1ubuntu0.1
tomcat10 –  10.1.40-1ubuntu1.26.04.1
25.10 questing libtomcat10-embed-java –  10.1.40-1ubuntu1.25.10.1
libtomcat10-java –  10.1.40-1ubuntu1.25.10.1
libtomcat9-java –  9.0.95-1ubuntu1.1
tomcat10 –  10.1.40-1ubuntu1.25.10.1
24.04 LTS noble libtomcat10-embed-java –  10.1.16-1ubuntu0.1~esm4  
libtomcat10-java –  10.1.16-1ubuntu0.1~esm4  
libtomcat9-java –  9.0.70-2ubuntu0.1+esm3  
tomcat10 –  10.1.16-1ubuntu0.1~esm4  
22.04 LTS jammy libtomcat9-embed-java –  9.0.58-1ubuntu0.2+esm4  
libtomcat9-java –  9.0.58-1ubuntu0.2+esm4  
tomcat9 –  9.0.58-1ubuntu0.2+esm4  
20.04 LTS focal libtomcat9-embed-java –  9.0.31-1ubuntu0.9+esm3  
libtomcat9-java –  9.0.31-1ubuntu0.9+esm3  
tomcat9 –  9.0.31-1ubuntu0.9+esm3  
18.04 LTS bionic libtomcat9-embed-java –  9.0.16-3ubuntu0.18.04.2+esm8  
libtomcat9-java –  9.0.16-3ubuntu0.18.04.2+esm8  
tomcat9 –  9.0.16-3ubuntu0.18.04.2+esm8  

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