Should you update to watchOS 27?
No: install watchOS 27.2 instead. watchOS 27 is a security update Apple released on 14 Sep 2026 for Apple Watch. It fixes 106 security flaws.[1] None of them is known to be used in attacks.
It has since been replaced by watchOS 27.2, released 26 Oct 2026, which includes all of its fixes. If you’re on an older version, install that instead.
Should you update?
No: install watchOS 27.2 instead. watchOS 27.2 came out on 26 Oct 2026 and includes every fix in watchOS 27, so there’s no reason to stop at this one. Software Update offers the newest version your device can run.
Is watchOS 27 still safe?
Not any more. watchOS 27.2 fixes 62 security flaws that watchOS 27 doesn’t, and each became public the day its fix shipped. Installing it is safe: get it only from the Watch app on your iPhone, under General → Software Update, never from a link in an email, text or pop-up.
What it fixes
Apple lists 106 security flaws across 49 parts of watchOS. For each, Apple says what an attacker could have done before the fix.[1]
| Part | Flaws | What an attacker could do |
|---|---|---|
| Kernel | 24 | An app may be able to cause unexpected system termination or corrupt kernel memory |
| WebKit | 7 | Processing maliciously crafted web content may lead to an unexpected process termination |
| SceneKit | 6 | Processing a maliciously crafted file may result in disclosure of process memory |
| ImageIO | 5 | Processing a maliciously crafted image may result in disclosure of process memory |
| AVEVideoEncoder | 3 | An app may be able to cause unexpected system termination |
| Bluetooth | 3 | A remote attacker may be able to cause unexpected app termination or arbitrary code execution |
| CoreUI | 3 | Processing a maliciously crafted file may lead to unexpected app termination |
| Accelerate Framework | 2 | Processing a maliciously crafted image may lead to unexpected process termination |
| CloudKit | 2 | A local app may be able to read a persistent account identifier |
| Core Bluetooth | 2 | An app may be able to access Bluetooth device information |
| CoreMedia | 2 | A sandboxed process may be able to circumvent sandbox restrictions |
| CoreText | 2 | Processing web content may lead to a denial-of-service |
| FontParser | 2 | Processing a maliciously crafted font file may lead to unexpected app termination |
| IOMobileFrameBuffer | 2 | An app may be able to cause unexpected system termination or corrupt kernel memory |
| NetworkExtension | 2 | An app may be able to access sensitive user data |
| 34 other parts | 39 |
How to update, and how long it takes
Anywhere from a few minutes to an hour. Watch updates are slow, so start one when you won’t need the watch for a while.
- Update your iPhone first.The watch needs the matching iPhone update.
- Open the Watch app on your iPhone.General → Software Update. Keep the watch on its charger and near the phone.
- Turn on automatic updates.In the same place, under Automatic Updates.
To check it worked: Watch app → General → About shows the watchOS version. It should say 27.2 or later.
Before and after
- After: watchOS 27.2, 26 Oct 2026, 62 security flaws
- watchOS updates, every release and the latest version
- Updates, the latest version of everything HARD tracks
References
- ^ Apple. “About the security content of watchOS 27”, 14 Sep 2026.