Ubuntu USN · USN-8253-1

Postfix vulnerability

Published: Thu, 07 May 2026 14:31

CVE-2026-43964

Summary

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

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.

Recommended actions per Ubuntu release

StackPatch playbook auto-generated per release codename and per affected package.

Ubuntu jammy

postfix→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-cdb→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-cdb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-doc→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-doc
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-ldap→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-ldap
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-lmdb→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-lmdb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-mysql→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-mysql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-pcre→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-pcre
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-pgsql→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-pgsql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-sqlite→3.6.4-1ubuntu1.4apt_upgrade
Standard apt upgrade. Install 3.6.4-1ubuntu1.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-sqlite
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu noble

postfix→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-cdb→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-cdb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-doc→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-doc
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-ldap→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-ldap
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-lmdb→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-lmdb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-mysql→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-mysql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-pcre→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-pcre
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-pgsql→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-pgsql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-sqlite→3.8.6-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 3.8.6-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-sqlite
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu questing

postfix→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-cdb→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-cdb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-doc→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-doc
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-ldap→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-ldap
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-lmdb→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-lmdb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-mongodb→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-mongodb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-mysql→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-mysql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-pcre→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-pcre
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-pgsql→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-pgsql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-sqlite→3.10.2-1ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.2-1ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-sqlite
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu resolute

postfix→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-cdb→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-cdb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-doc→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-doc
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-ldap→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-ldap
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-lmdb→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-lmdb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-mongodb→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-mongodb
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-mysql→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-mysql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-pcre→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-pcre
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-pgsql→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-pgsql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
postfix-sqlite→3.10.6-4ubuntu2.1apt_upgrade
Standard apt upgrade. Install 3.10.6-4ubuntu2.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y postfix-sqlite
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Are YOU affected by USN-8253-1?

5-second check on your actual server. Reads /etc/os-release, uname -r, and dpkg-query; matches against the live USN + Debian Security Tracker feeds; tells you whether USN-8253-1 (and any other live CVE) applies. Anonymous, no signup.

curl https://mindsparkstack.com/scan.sh | bash

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