[USN-7844-1] YAML::Syck vulnerability

==========================================================================
Ubuntu Security Notice USN-7844-1
October 28, 2025

libyaml-syck-perl vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 25.10
- Ubuntu 25.04
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

The system could be made to expose sensitive information.

Software Description:
- libyaml-syck-perl: Perl module providing a fast, lightweight YAML loader and dumper

Details:

It was discovered that YAML::Syck did not properly handle parsing YAML
files. An attacker could possibly use this issue to expose sensitive
information.

Update instructions:

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

Ubuntu 25.10
libyaml-syck-perl 1.34-3ubuntu0.1

Ubuntu 25.04
libyaml-syck-perl 1.34-2ubuntu0.25.04.1

Ubuntu 24.04 LTS
libyaml-syck-perl 1.34-2ubuntu0.24.04.1~esm1
Available with Ubuntu Pro

Ubuntu 22.04 LTS
libyaml-syck-perl 1.34-1ubuntu0.1~esm1
Available with Ubuntu Pro

Ubuntu 20.04 LTS
libyaml-syck-perl 1.31-1ubuntu0.1~esm1
Available with Ubuntu Pro

Ubuntu 18.04 LTS
libyaml-syck-perl 1.29-1ubuntu0.18.04.1~esm1
Available with Ubuntu Pro

Ubuntu 16.04 LTS
libyaml-syck-perl 1.29-1ubuntu0.16.04.1~esm1
Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-7844-1
CVE-2025-11683

Package Information:
https://launchpad.net/ubuntu/+source/libyaml-syck-perl/1.34-3ubuntu0.1
https://launchpad.net/ubuntu/+source/libyaml-syck-perl/1.34-2ubuntu0.25.04.1