watchOS 26.4 Security Update

What watchOS 26.4 Fixes

watchOS 26.4, released March 24, 2026, fixes 25 vulnerabilities in 19 parts of the system, according to Apple's security advisory.

Apple does not say that any of them were exploited before the fix. That makes watchOS 26.4 a routine security update: worth installing soon, not an emergency.

It has since been superseded: the newest security release for watchOS 26 is watchOS 26.6, from July 27, 2026, which includes these fixes.

Grouped by us from the impact Apple gives for each fix; the impact lines below are Apple's own.

Which Devices Get watchOS 26.4

Apple lists watchOS 26.4 for: Apple Watch Series 6 and later.

How to Install watchOS 26.4

Open the Watch app on the paired iPhone, then General → Software Update. The watch needs to be on its charger and within range of the iPhone.

Security fixes are cumulative: any later release for the same version includes these as well, so if you are already past watchOS 26.4 there is nothing to do.

Every Fix in watchOS 26.4

All 25 CVEs in Apple's advisory, the most serious kinds first. Each entry is the part of the system affected, Apple's description of the impact and the fix, and the CVE ID.

• 802.1X

  An attacker in a privileged network position may be able to intercept network traffic

  An authentication issue was addressed with improved state management.

  CVE-2026-28865

• CoreUtils

  A user in a privileged network position may be able to cause a denial-of-service

  A null pointer dereference was addressed with improved input validation.

  CVE-2026-28886

• Kernel

  An app may be able to disclose kernel memory

  A logging issue was addressed with improved data redaction.

  CVE-2026-28868

• Kernel

  An app may be able to cause unexpected system termination or corrupt kernel memory

  The issue was addressed with improved memory handling.

  CVE-2026-20698

• Kernel

  An app may be able to cause unexpected system termination or write kernel memory

  A use after free issue was addressed with improved memory management.

  CVE-2026-20687

• ppp

  An attacker may be able to cause unexpected system termination or read kernel memory

  The issue was addressed with improved memory handling.

  CVE-2026-28896

• WebKit

  A malicious website may be able to process restricted web content outside the sandbox

  The issue was addressed with improved memory handling.

  CVE-2026-28859

• Accounts

  An app may be able to access sensitive user data

  An authorization issue was addressed with improved state management.

  CVE-2026-28877

• curl

  An issue existed in curl which may result in unintentionally sending sensitive information via an incorrect connection

  This is a vulnerability in open source code and Apple Software is among the affected projects. The CVE-ID was assigned by a third party. Learn more about the issue and CVE-ID at cve.org .

  CVE-2025-14524

• FaceTime

  An attacker with physical access to a locked Apple Watch may be able to view user contacts

  This issue was addressed with improved permissions checking.

  CVE-2026-43679

• GeoServices

  An app may be able to access sensitive user data

  An information leakage was addressed with additional validation.

  CVE-2026-28870

• Kernel

  An app may be able to leak sensitive kernel state

  This issue was addressed with improved authentication.

  CVE-2026-28867

• Security

  A local attacker may gain access to user's Keychain items

  This issue was addressed with improved permissions checking.

  CVE-2026-28864

• Security

  A local attacker may be able to modify the state of the Keychain

  The issue was addressed with improved input validation.

  CVE-2026-28860

• Siri

  An attacker with physical access to a locked device may be able to view sensitive user information

  The issue was addressed with improved authentication.

  CVE-2026-28856

• Audio

  Processing maliciously crafted web content may lead to an unexpected process crash

  A use-after-free issue was addressed with improved memory management.

  CVE-2026-28879

• Audio

  An attacker may be able to cause unexpected app termination

  A type confusion issue was addressed with improved memory handling.

  CVE-2026-28822

• ImageIO

  Processing a maliciously crafted file may lead to unexpected app termination

  This is a vulnerability in open source code and Apple Software is among the affected projects. The CVE-ID was assigned by a third party. Learn more about the issue and CVE-ID at cve.org .

  CVE-2025-64505

• UIFoundation

  An app may be able to cause a denial-of-service

  A stack overflow was addressed with improved input validation.

  CVE-2026-28852

• CoreMedia

  Processing an audio stream in a maliciously crafted media file may terminate the process

  An out-of-bounds access issue was addressed with improved bounds checking.

  CVE-2026-20690

• Crash Reporter

  An app may be able to enumerate a user's installed apps

  A privacy issue was addressed by removing sensitive data.

  CVE-2026-28878

• libxpc

  An app may be able to enumerate a user's installed apps

  This issue was addressed with improved checks.

  CVE-2026-28882

• Sandbox Profiles

  An app may be able to fingerprint the user

  A permissions issue was addressed with additional restrictions.

  CVE-2026-28863

• WebKit

  Processing maliciously crafted web content may prevent Content Security Policy from being enforced

  This issue was addressed through improved state management.

  CVE-2026-20665

• WebKit Sandboxing

  A maliciously crafted webpage may be able to fingerprint the user

  An authorization issue was addressed with improved state management.

  CVE-2026-20691

watchOS 26 Security Release History

watchOS 26.4 in context: the security releases Apple has published for watchOS 26, newest first, with the number of fixes each carried.

The Same Fixes Elsewhere

Apple ships most fixes to every platform that shares the code, and to older versions still under support. These releases close at least one of the same CVEs:

Frequently Asked Questions