You're going to want to update your Mac to address a serious Screen Sharing vulnerability that could letter a malicious actor initiate screen sharing without authentic credentials.
This week Apple released macOS Sonoma 14.8.9, macOS Sequoia 15.7.9, and macOS Tahoe 26.6.1 with release notes. Notably, all three releases claim that Apple made "important security fixes" and recommended the updates for everyone.
"Impact: An attacker on the network may be able to authenticate to Screen Sharing without valid credentials
Description: An authentication issue was addressed with improved state management."
That message is the same across all three versions of macOS.
It doesn't appear that the bug has been exploited in the wild, but if you haven't updated your Mac recently, now is the time to do so. Based on Apple's description, it appears that a bad actor could bypass Screen Sharing authentication checks, which would give them remote access to your computer.
Potentially, this would allow them to view the screen, open apps or files or perform other actions on the computer.
You may not use screen sharing, but it's still a good idea to install this update. Apple clearly deemed the flaw serious enough to patch three different versions of macOS before the next round of major OS updates.
Keep your Mac safe
To keep your Mac safe you may want to ensure that updates are automatically applied. Understandably if you're cautious about updates before they're settled you may wait. So you'll want to track updates and make sure you get the security-focused ones to protect your computer.
For screen sharing specifically, this vulnerability may have been able to sneak around you. But if you do any screen sharing, make sure it's with a trusted partner that you know to protect your computer. Additionally, keep any sensitive information closed before passing permissions just as a way to introduce a little bit of a block.
At the end of your session, double-check that screen sharing is turned off.
Beyond that, Apple does have Gatekeeper built-in which can block or warn you before you install unverified apps from the web. Still, you might want to consider using one of the best Mac antivirus software along side Apple's built-in ones.
Again, these macOS updates are available right now, so make sure you've installed them.
