USN-7959-1: klibc vulnerabilities

Publication date

14 January 2026

Overview

klibc could be made to crash if it received specially crafted input.


Packages

  • klibc - Minimalistic libc subset for use with initramfs

Details

It was discovered that zlib, vendored in klibc, did not properly handle
integer arithmetic. An attacker could possibly use this issue to execute
arbitrary code or cause a denial of service.

It was discovered that zlib, vendored in klibc, did not properly handle
integer arithmetic. An attacker could possibly use this issue to execute
arbitrary code or cause a denial of service.

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
25.10 questing klibc-utils –  2.0.14-1ubuntu1.1
libklibc –  2.0.14-1ubuntu1.1
25.04 plucky klibc-utils –  2.0.13-4ubuntu1.1
libklibc –  2.0.13-4ubuntu1.1
24.04 LTS noble klibc-utils –  2.0.13-4ubuntu0.2
libklibc –  2.0.13-4ubuntu0.2
22.04 LTS jammy klibc-utils –  2.0.10-4ubuntu0.2
libklibc –  2.0.10-4ubuntu0.2
20.04 LTS focal klibc-utils –  2.0.7-1ubuntu5.2+esm1  
libklibc –  2.0.7-1ubuntu5.2+esm1  
18.04 LTS bionic klibc-utils –  2.0.4-9ubuntu2.2+esm2  
libklibc –  2.0.4-9ubuntu2.2+esm2  
16.04 LTS xenial klibc-utils –  2.0.4-8ubuntu1.16.04.4+esm3  
libklibc –  2.0.4-8ubuntu1.16.04.4+esm3  
14.04 LTS trusty klibc-utils –  2.0.3-0ubuntu1.14.04.3+esm4  
libklibc –  2.0.3-0ubuntu1.14.04.3+esm4  

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