Apple releases Background Security Improvements for iOS, iPadOS, and macOS 26.3.1, macOS 26.3.2

This document describes the content of Background Security Improvements.

About Background Security Improvements​

Background Security Improvements deliver important security improvements between software updates and are available only for the latest versions of iOS, iPadOS, and macOS. Learn more about Background Security Improvements. Releases for which we publish security advisories are also included on the Apple security releases page.

iOS 26.3.1 (a), iPadOS 26.3.1 (a), macOS 26.3.1 (a), macOS 26.3.2 (a)​

Released March 17, 2026

WebKit​

Available for: iOS 26.3.1, iPadOS 26.3.1, macOS 26.3.1, macOS 26.3.2

Impact: Processing maliciously crafted web content may bypass Same Origin Policy

Description: A cross-origin issue in the Navigation API was addressed with improved input validation.

WebKit Bugzilla: 306050
CVE-2026-20643: Thomas Espach