Ubuntu 26.04 LTS Sed Critical Overwrite Risk USN-8229-1 CVE-2026-5958

ubuntu

May 4, 2026

sed could be made to overwrite files.

Summary

sed could be made to overwrite files.

Software Description:

- sed: GNU stream editor for filtering/transforming text

Details:

Micha\u0142 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.

Topics Covered

security advisory critical remote access Ubuntu overwrite sed

Update Instructions

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

Ubuntu 26.04 LTS
  sed                             4.9-2ubuntu1

Ubuntu 25.10
  sed                             4.9-2ubuntu0.25.10.1

Ubuntu 24.04 LTS
  sed                             4.9-2ubuntu0.24.04.1

Ubuntu 22.04 LTS
  sed                             4.8-1ubuntu2.1

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