So I show here how I launched a fresh Ubuntu 24.04 in Google Cloud, on 2026-05-04, and demostrate the exploit of escalation privileges Copy Fail (CVE-2026-31431) which allows you to become root from a regular user account in almost any Linux since year 2017.

It consists in the execution of a Python 3 code, which is only 732 bytes.

I show how I fixed it by upgrading the kernel and rebooting.

Here you can see the original tweet I saw: https://x.com/DarkWebInformer/status/2049579219190165658?s=20

And access the code: https://github.com/theori-io/copy-fail-CVE-2026-31431

I also tried on a fresh deployed Ubuntu 26.04 LTS and it was not affected by the exploit.