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Fedora 39 37 35 33 31 Umbra Key Updates Access USN-9201-3

ubuntu
Calendar Grey April 2, 2026
Dist Ubuntu Esm H88
Undertow in Ubuntu allows unintended session access over the network, requiring immediate updates to mitigate risk.
Undertow would allow unintended access to user sessions over the network.

Summary

A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 24.04 LTS - Ubuntu 22.04 LTS - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS - Ubuntu 16.04 LTS Summary: Undertow would allow unintended access to user sessions over the network. Software Description: - undertow: Java web server based on non-blocking IO Details: It was discovered that Undertow incorrectly validated the Host header in incoming HTTP requests. A remote attacker could possibly use this issue to gain unintended access to user sessions.

Topics%20covered

Topics Covered

security advisory remote attack Ubuntu important session access undertow

Update Instructions

The problem can be corrected by updating your system to the following package versions: Ubuntu 24.04 LTS libundertow-java 2.3.8-2ubuntu0.1~esm1 Available with Ubuntu Pro Ubuntu 22.04 LTS libundertow-java 2.2.16-1ubuntu0.1~esm1 Available with Ubuntu Pro Ubuntu 20.04 LTS libundertow-java 2.0.29-1ubuntu0.1~esm1 Available with Ubuntu Pro Ubuntu 18.04 LTS libundertow-java 1.4.23-3ubuntu0.1~esm1 Available with Ubuntu Pro Ubuntu 16.04 LTS libundertow-java 1.3.16-1ubuntu0.1~esm1 Available with Ubuntu Pro In general, a standard system update will make all the necessary changes.

References

https://ubuntu.com/security/notices/USN-8144-1

CVE-2025-12543

Severity
important
Lowest
Low
Medium
High
Critical

Ubuntu Security Notice USN-8144-1

Topics%20covered

Topics Covered

security advisory remote attack Ubuntu important session access undertow

Package Information

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