CVE-2026-20643 Security feature bypass in Safari

Medium 5.4 Published Updated

Attackers can bypass Same Origin Policy by processing malicious web content, requiring users to update Apple browsers and operating systems.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2026-20643?

CVE-2026-20643 is a medium-severity vulnerability in Apple Ipados, published on 17 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

A cross-origin issue in the Navigation API was addressed with improved input validation. This issue is fixed in Background Security Improvements for iOS, iPadOS, and macOS, Safari 26.4, iOS 18.7.7 and iPadOS 18.7.7, iOS 26.4 and iPadOS 26.4, macOS Tahoe 26.4, visionOS 26.4. Processing maliciously crafted web content may bypass Same Origin Policy.

Weakness: CWE-346, CWE-20

Which versions are affected by CVE-2026-20643?

It affects 3 products.

Products include Apple Ipados, Apple Iphone Os, Apple Macos.

How do I fix CVE-2026-20643?

Upgrade to a fixed version.

Is CVE-2026-20643 being exploited?

There is no known exploitation of CVE-2026-20643 in the wild and no public exploit code.

Public exploit code: 2 proofs of concept on GitHub.

All Apple Ipados vulnerabilities

Sources

Also known as DEBIAN-CVE-2026-20643, GHSA-gvvx-mjmx-h5qh, UBUNTU-CVE-2026-20643.

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