Ubuntu 26.04 LTS Avahi Critical DoS Fix USN-8269-1 CVE-2026-24401

ubuntu

May 14, 2026

Several security issues were fixed in Avahi.

Summary

Several security issues were fixed in Avahi.

Software Description:

- avahi: IPv4LL network address configuration daemon

Details:

It is discovered that Avahi incorrectly handled crafted input. A

remote attacker could possibly use this issue to crash the program,

resulting in a denial of service. This issue only affected Ubuntu

14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS,

Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-24401)

Guillaume Meunier discovered that Avahi incorrectly handled crafted

input. An attacker could possibly use this issue to crash the

program, resulting in a denial of service. (CVE-2026-34933)

Topics Covered

security advisory denial of service critical Ubuntu avahi

Update Instructions

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

Ubuntu 26.04 LTS
  avahi-daemon                    0.8-18ubuntu1.1

Ubuntu 25.10
  avahi-daemon                    0.8-16ubuntu3.2

Ubuntu 24.04 LTS
  avahi-daemon                    0.8-13ubuntu6.2

Ubuntu 22.04 LTS
  avahi-daemon                    0.8-5ubuntu5.5

Ubuntu 20.04 LTS
  avahi-daemon                    0.7-4ubuntu7.3+esm2
                                  Available with Ubuntu Pro

Ubuntu 18.04 LTS
  avahi-daemon                    0.7-3.1ubuntu1.3+esm4
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  avahi-daemon                    0.6.32~rc+dfsg-1ubuntu2.3+esm5
                                  Available with Ubuntu Pro

Ubuntu 14.04 LTS
  avahi-daemon                    0.6.31-4ubuntu1.3+esm5
                                  Available with Ubuntu Pro