USN-8521-1: Libidn vulnerability

Publication date

9 July 2026

Overview

Libidn could be made to crash or expose sensitive information if it received specially crafted input.


Packages

  • libidn - implementation of IETF IDN specifications

Details

It was discovered that Libidn incorrectly handled certain internationalized
domain name strings. An attacker could possibly use this issue to obtain
sensitive information or cause a denial of service.

It was discovered that Libidn incorrectly handled certain internationalized
domain name strings. An attacker could possibly use this issue to obtain
sensitive information 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
26.04 LTS resolute libidn12 –  1.43-2ubuntu0.26.04.1
24.04 LTS noble libidn12 –  1.42-1ubuntu0.1
22.04 LTS jammy libidn12 –  1.38-4ubuntu1.1

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