Apple has released a set of security updates for macOS that fix a vulnerability in Screen Sharing, its built-in remote-access feature. The flaw could allow an attacker on the same network to bypass authentication and gain access to Screen Sharing without valid credentials.
The issue is tracked as CVE-2026-65400 and affects multiple versions of macOS. Apple has released macOS Tahoe 26.6.1, macOS Sequoia 15.7.9, and macOS Sonoma 14.8.9, all addressing the same vulnerability.
Apple says the vulnerability only potentially affects users who have manually enabled Screen Sharing before installing the update. An attacker would generally need to be on the same network as the targeted Mac, which limits the likelihood of a remote attack from the internet. Private home and corporate networks would also typically block the connections needed to exploit the flaw.
Still, the circumstances around the patch make it worth installing rather than putting it off.
The flaw affects a feature that can control your Mac
Screen Sharing allows another connected user to view and control a Mac remotely. Once enabled, it can provide access to the desktop, files and windows, applications, and even the ability to restart the computer. That makes an authentication bypass considerably more serious than a vulnerability affecting an isolated component.
PoC for a critical vulnerability in Apple macOS Screen Sharing (CVE-2026-65400).
If Screen Sharing is enabled, any network attacker can exploit the bug to log in as any account, without knowing the password.
We reverse engineered Apple’s unusual macOS 26.6.1 patch to understand… pic.twitter.com/WRIIwKx6yI
— Calif (@calif_io) August 8, 2026
The vulnerability was reported by Alfredo Pesoli, co-founder and CEO of cybersecurity startup Bynario. Apple says it is not aware of the flaw being exploited outside test environments, and an Apple spokesperson told Inc. that users who have not manually enabled Screen Sharing are not impacted.
There is also no public proof-of-concept exploit available as of the report. That is reassuring, but it doesn’t make the update something worth ignoring.
The unusual timing is the bigger warning.
Apple released the patch outside its normal software-update cycle, and its published security notes list only this vulnerability. That caught the attention of Phil Stokes, a research engineer at cybersecurity company SentinelOne, who told Inc. that the timing “suggests some urgency.” He said enterprises should consider it a patching priority depending on whether Screen Sharing is enabled and reachable.
MacBook Air M5 Moinak Pal/Digital Trends
For Mac users, updating is straightforward. Go to System Settings > General > Software Update and install the latest version compatible with your Mac. Apple itself recommends keeping macOS current as one of the most important steps users can take to maintain security.
The update arrives ahead of Apple’s larger software releases this fall, including macOS 27 and iOS 27, which will introduce features such as Siri AI and expanded on-device intelligence. Those updates may get more attention, but this smaller security patch is arguably the one Mac users should deal with first.