USN-8229-2: sed vulnerability

Publication date

28 May 2026

Overview

sed could be made to overwrite files.


Packages

  • sed - GNU stream editor for filtering/transforming text

Details

USN-8229-1 fixed a vulnerability in sed. This update provides the
corresponding update for Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.

Original advisory details:

Michał Majchrowicz and Marcin Wyczechowski discovered that sed
incorrectly handled symbolic links when performing in-place edits.
A local attacker could possibly use this issue to overwrite
arbitrary files.

USN-8229-1 fixed a vulnerability in sed. This update provides the
corresponding update for Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.

Original advisory details:

Michał Majchrowicz and Marcin Wyczechowski discovered that sed
incorrectly handled symbolic links when performing in-place edits.
A local attacker could possibly use this issue to overwrite
arbitrary files.

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
20.04 LTS focal sed –  4.7-1ubuntu0.1~esm1  
18.04 LTS bionic sed –  4.4-2ubuntu0.1~esm1  

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