We’ve already patched for Linux vulnerability ‘Copy Fail’

A newly discovered vulnerability threatens every Linux distribution shipped since 2017.

The researchers who discovered the vulnerability, known as CVE-2026-31431 or Copy Fail, said that the vulnerability makes it possible for “unprivileged local users [to] write four controlled bytes into the page cache of any readable file on a Linux system, and use that to gain root access”.

Basically, this bug allows users to manipulate four tiny pieces of data in the server's temporary memory. This is where the server stores copies of important system files. A malicious user can make this data change a system's rules, tricking the server into giving them complete control.

Using Web Hosting or Email Hosting? You're covered

If you're a Web Hosting or Email Hosting customer with MyHost, this isn't something you need to worry about.

We regularly patch our cPanel servers for all relevant reported vulnerabilities, so Copy Fail won't affect you and you can relax.

Managed VPS and Dedicated Servers are already patched

We've acted fast and patched Linux on all managed servers (Virtual Servers, Dedicated Servers). In all of these cases, Copy Fail is no longer a vulnerability.

If you have any unmanaged servers, it’s your responsibility to patch Linux. We recommend acting as quickly as possible.

• Running Ubuntu? See their CVE-2026-31431 security page.
• The Debian security tracker shows which versions are fixed.
• For AlmaLinux the situation can be different. If you’re running CloudLinux on top of AlmaLinux, Copy Fail is less severe but you will need to check through binaries that are allowed for individual users. If you’re running AlmaLinux alone, the severity is as high as for any other distro. They're yet to release a fix as we’re writing this, but we will keep an eye on their progress.

You can expect more of this

Thanks to automated, AI-driven tools, hundreds of new software vulnerabilities are now reported every day. Copy Fail is a good example of a severe vulnerability that went undiscovered for almost a decade before modern technology made it so much easier to probe for weaknesses.

If you're managing your own servers, you need to be prepared for a future where common vulnerabilties are harder to keep up with, urgent patching is required more often, and malicious actors are better equipped than ever.

With Managed Services, patches like these almost take care of themselves

This is another example of how valuable Managed Services can be when high severity bugs are found. If we manage your Virtual Private Server, or Dedicated Server for you, we jump to attention on your behalf. In an ideal world you wouldn’t even hear about bugs like Copy Fail until after we’ve quickly protected your server against them.

Get in touch with us today and we can talk about adding Managed Services and taking worries like Copy Fail off your mind.

Photo by Enith from Pixabay.