After I left work today, I noticed a flood of messages about a vulnerability in the xz package that a few dozen of my Homebrew packages used.

I find these security alerts hard to read and understand, but here is what you need to do if you are on macOS and using Homebrew.

Thankfully, the Homebrew community already has a fix in place, and all we need to do is update Homebrew and install the latest upgrades of any packages linked/built against xz version 5.6.x.

For more details, check out Security Alert: Potential SSH Backdoor via LIBLZMA.

Am I vulnerable?

From your terminal run:

brew info xz
==> xz: stable 5.4.6 (bottled)

If your xz version is 5.4.x, you are safe. 👍

If your xz version is 5.6.x, do not pass; go and update your Homebrew immediately. 👎

To update your Homebrew version

brew update
brew upgrade

brew info xz
==> xz: stable 5.4.6 (bottled)

Post Homebrew upgrade

Once you are done, I recommend rebooting your Mac and installing any recent macOS updates.