CVE-2026-20643

VendorappleProductmacos, iphone os, ipadosDiscoveredMar 17, 2026UpdatedMar 25, 2026

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.

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CVSS v3.1

5.4 MEDIUM

EPSS

0.36%

probability of exploitation in 30 days

CISA KEV

Not listed

no confirmed exploitation reported

News coverage

sources referencing this CVE

Related IOCs

seen in the same coverage

EPSS Trend

Aug 16, 2026 → Oct 22, 2026

● 0.01pp

0.35% → 0.36% over 2 tracked changes

CVSS v3.1 Detail

Attack VectorNETWORK

Attack ComplexityLOW

Privileges RequiredNONE

User InteractionREQUIRED

ScopeUNCHANGED

ConfidentialityLOW

IntegrityLOW

AvailabilityNONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Connections

7 relationships

CWE-20

source

Timeline

disclosure → media coverage

Mar 17, 2026

Disclosure — published as a CVE record. · last revised by NVD Mar 25, 2026

Mar 18, 2026

bleepingcomputer.com reports: Apple pushes first Background Security Improvements update to fix WebKit flaw

Mar 18, 2026

thehackernews.com reports: Apple Fixes WebKit Vulnerability Enabling Same-Origin Policy Bypass on iOS and macOS

Mar 18, 2026

malwarebytes.com reports: Apple patches WebKit bug that could let sites access your data

Public PoC (2)

github.com/0xjohnnydev/WebKit-NavigationAPI-SOP-Bypass github.com/Fliv/CVE-2026-20643

Unverified third-party code — review before executing.