About the security content of watchOS 26.3

This document describes the security content of watchOS 26.3.

About Apple security updates

For our customers' protection, Apple doesn't disclose, discuss, or confirm security issues until an investigation has occurred and patches or releases are available. Recent releases are listed on the Apple security releases page.

Apple security documents reference vulnerabilities by CVE-ID when possible.

For more information about security, see the Apple Product Security page.

watchOS 26.3

Bluetooth

Available for: Apple Watch Series 6 and later

Impact: An attacker in a privileged network position may be able to perform denial-of-service attack using crafted Bluetooth packets

Description: A denial-of-service issue was addressed with improved validation.

CVE-2026-20650: jioundai

CoreAudio

Available for: Apple Watch Series 6 and later

Impact: Processing a maliciously crafted media file may lead to unexpected app termination or corrupt process memory

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

CVE-2026-20611: Anonymous working with Trend Micro Zero Day Initiative

CoreMedia

Available for: Apple Watch Series 6 and later

Impact: Processing a maliciously crafted file may lead to a denial-of-service or potentially disclose memory contents

Description: The issue was addressed with improved memory handling.

CVE-2026-20609: Yiğit Can YILMAZ (@yilmazcanyigit)

CoreServices

Available for: Apple Watch Series 6 and later

Impact: An app may be able to gain root privileges

Description: A race condition was addressed with improved state handling.

CVE-2026-20617: Gergely Kalman (@gergely_kalman), Csaba Fitzl (@theevilbit) of Iru

CoreServices

Available for: Apple Watch Series 6 and later

Impact: An app may be able to access sensitive user data

Description: An issue existed in the handling of environment variables. This issue was addressed with improved validation.

CVE-2026-20627: an anonymous researcher

dyld

Available for: Apple Watch Series 6 and later

Impact: An attacker with memory write capability may be able to execute arbitrary code. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals on versions of iOS before iOS 26. CVE-2025-14174 and CVE-2025-43529 were also issued in response to this report.

Description: A memory corruption issue was addressed with improved state management.

CVE-2026-20700: Google Threat Analysis Group

Game Center

Available for: Apple Watch Series 6 and later

Impact: A user may be able to view sensitive user information

Description: A logging issue was addressed with improved data redaction.

CVE-2026-20649: Asaf Cohen

ImageIO

Available for: Apple Watch Series 6 and later

Impact: Processing a maliciously crafted image may lead to disclosure of user information

Description: The issue was addressed with improved bounds checks.

CVE-2026-20675: George Karchemsky (@gkarchemsky) working with Trend Micro Zero Day Initiative

ImageIO

Available for: Apple Watch Series 6 and later

Impact: Processing a maliciously crafted image may result in disclosure of process memory

Description: The issue was addressed with improved memory handling.

CVE-2026-20634: George Karchemsky (@gkarchemsky) working with Trend Micro Zero Day Initiative

Kernel

Available for: Apple Watch Series 6 and later

Impact: An app may be able to cause unexpected system termination

Description: The issue was addressed with improved memory handling.

CVE-2026-20654: Jian Lee (@speedyfriend433)

Kernel

Available for: Apple Watch Series 6 and later

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

Description: A logic issue was addressed with improved checks.

CVE-2026-20671: Xin'an Zhou, Juefei Pu, Zhutian Liu, Zhiyun Qian, Zhaowei Tan, Srikanth V. Krishnamurthy, Mathy Vanhoef

libexpat

Available for: Apple Watch Series 6 and later

Impact: Processing a maliciously crafted file may lead to a denial-of-service

Description: 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-2025-59375

libxpc

Available for: Apple Watch Series 6 and later

Impact: An app may be able to break out of its sandbox

Description: A logic issue was addressed with improved checks.

CVE-2026-20667: an anonymous researcher

Sandbox

Available for: Apple Watch Series 6 and later

Impact: An app may be able to break out of its sandbox

Description: A permissions issue was addressed with additional restrictions.

CVE-2026-20628: Noah Gregory (wts.dev)

StoreKit

Available for: Apple Watch Series 6 and later

Impact: An app may be able to identify what other apps a user has installed

Description: A privacy issue was addressed with improved checks.

CVE-2026-20641: Gongyu Ma (@Mezone0)

WebKit

Available for: Apple Watch Series 6 and later

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

Description: The issue was addressed with improved memory handling.

CVE-2026-20635: EntryHi

Additional recognition

Bluetooth

We would like to acknowledge Tommaso Sacchetti for their assistance.

Kernel

We would like to acknowledge Joseph Ravichandran (@0xjprx) of MIT CSAIL, Xinru Chi of Pangu Lab for their assistance.

libpthread

We would like to acknowledge Fabiano Anemone for their assistance.

NetworkExtension

We would like to acknowledge Gongyu Ma (@Mezone0) for their assistance.

Transparency

We would like to acknowledge Wojciech Regula of SecuRing (wojciechregula.blog) for their assistance.

Wallet

We would like to acknowledge Lorenzo Santina (@BigNerd95) and Marco Bartoli (@wsxarcher) for their assistance.

WebKit

We would like to acknowledge EntryHi, Luigino Camastra of Aisle Research, Stanislav Fort of Aisle Research, Vsevolod Kokorin (Slonser) of Solidlab and Jorian Woltjer for their assistance.