Ubuntu 26.04 LTS Postfix Key Denial of Service Vulnerability USN-8253-1

ubuntu

May 7, 2026

Postfix could be made to crash if it received specially crafted network traffic.

Summary

Postfix could be made to crash if it received specially crafted network

traffic.

Software Description:

- postfix: High-performance mail transport agent

Details:

Kamil Frankowicz discovered that Postfix incorrectly handled certain

enhanced status codes. A remote attacker could possibly use this issue to

cause Postfix to crash, resulting in a denial of service.

Topics Covered

security advisory denial of service remote attack Ubuntu important postfix

Update Instructions

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

Ubuntu 26.04 LTS
  postfix                         3.10.6-4ubuntu2.1

Ubuntu 25.10
  postfix                         3.10.2-1ubuntu2.1

Ubuntu 24.04 LTS
  postfix                         3.8.6-1ubuntu0.1

Ubuntu 22.04 LTS
  postfix                         3.6.4-1ubuntu1.4

In general, a standard system update will make all the necessary changes.