USN-8733-2: Gzip vulnerabilities

Publication date

22 September 2026

Overview

Several security issues were fixed in Gzip.


Packages

  • gzip - GNU compression utilities

Details

USN-8733-1 fixed vulnerabilities in Gzip. This update provides the
corresponding fix for Gzip on Ubuntu 14.04 LTS, Ubuntu 18.04 LTS and Ubuntu
20.04 LTS.

Original advisory details:

Michał Majchrowicz and Marcin Wyczechowski discovered that Gzip's gzexe
utility created temporary files in an insecure manner when mktemp was
unavailable. A local attacker could possibly use this issue to overwrite
arbitrary files. (CVE-2026-41991)

Elias Hasas, Michał Majchrowicz and Marcin Wyczechowski discovered that
Gzip incorrectly handled certain compressed files. An attacker could
possibly use this issue to obtain sensitive information or cause Gzip to
crash, resulting in a denial of service. (CVE-2026-41992)

USN-8733-1 fixed vulnerabilities in Gzip. This update provides the
corresponding fix for Gzip on Ubuntu 14.04 LTS, Ubuntu 18.04 LTS and Ubuntu
20.04 LTS.

Original advisory details:

Michał Majchrowicz and Marcin Wyczechowski discovered that Gzip's gzexe
utility created temporary files in an insecure manner when mktemp was
unavailable. A local attacker could possibly use this issue to overwrite
arbitrary files. (CVE-2026-41991)

Elias Hasas, Michał Majchrowicz and Marcin Wyczechowski discovered that
Gzip incorrectly handled certain compressed files. An attacker could
possibly use this issue to obtain sensitive information or cause Gzip to
crash, resulting in a denial of service. (CVE-2026-41992)

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
20.04 LTS focal gzip –  1.10-0ubuntu4.1+esm1  
18.04 LTS bionic gzip –  1.6-5ubuntu1.2+esm1  
14.04 LTS trusty gzip –  1.6-3ubuntu1+esm2  

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