---
id: CVE-2026-20643
title: >-
  A cross-origin issue in the Navigation API was addressed with improved input
  validation
summary: >-
  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 2…
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N'
cvssSource: adp
vendor: Apple
product: Safari
affected:
  - Safari < 26.4
  - ios_and_ipados < 18.7.7
  - ios_and_ipados < 26.3.1 (a)
  - ios_and_ipados < 26.4
  - macOS < 26.3.1 (a)
  - macOS < 26.3.2 (a)
  - macOS < 26.4
  - visionOS < 26.4
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-03-18T13:14:53.546083Z'
exploitAvailable: true
published: '2026-03-17'
updated: '2026-10-26'
sourceUpdated: '2026-10-26T20:40:02.537Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-20643'
references:
  - url: 'https://support.apple.com/en-us/126604'
  - url: 'https://support.apple.com/en-us/126792'
  - url: 'https://support.apple.com/en-us/126793'
  - url: 'https://support.apple.com/en-us/126794'
  - url: 'https://support.apple.com/en-us/126799'
  - url: 'https://support.apple.com/en-us/126800'
tags:
  - cve.org
  - exploit-available
epss: 0.0036
epssPercentile: 0.29623
exploits:
  github: 2
  githubRepos:
    - 'https://github.com/0xjohnnydev/WebKit-NavigationAPI-SOP-Bypass'
    - 'https://github.com/Fliv/CVE-2026-20643'
  checkedAt: '2026-10-27T16:12:35.803Z'
ingestedAt: '2026-10-27T16:11:58.983Z'
---

## Overview

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.

## Affected

- `Safari < 26.4`
- `ios_and_ipados < 18.7.7`
- `ios_and_ipados < 26.3.1 (a)`
- `ios_and_ipados < 26.4`
- `macOS < 26.3.1 (a)`
- `macOS < 26.3.2 (a)`
- `macOS < 26.4`
- `visionOS < 26.4`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.