USN-8973-1: libmspack vulnerability

Publication date

3 November 2026

Overview

libmspack could be made to crash or run programs as your login if it opened a specially crafted file.


Packages

  • libmspack - library for Microsoft compression formats

Details

It was discovered that libmspack did not properly initialize pointers
when handling errors while reading KWAJ archive headers. An attacker
could possibly use this issue to cause libmspack to crash, resulting
in a denial of service, or execute arbitrary code.

It was discovered that libmspack did not properly initialize pointers
when handling errors while reading KWAJ archive headers. An attacker
could possibly use this issue to cause libmspack to crash, resulting
in a denial of service, or execute arbitrary code.

Update instructions

In general, a standard system update will 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
26.10 stonking libmspack0t64 –  0.11-1.1ubuntu0.26.10.1
26.04 LTS resolute libmspack0t64 –  0.11-1.1ubuntu0.26.04.1
24.04 LTS noble libmspack0t64 –  0.11-1.1ubuntu0.24.04.1
22.04 LTS jammy libmspack0 –  0.10.1-2ubuntu0.1

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