CVE-2026-20643: exploitation status and patch state

CVE-2026-20643 · CVSS 5.4 MEDIUM · EPSS <1%

A cross-origin issue in the Navigation API was addressed with improved input validation. This issue is fixed in Background Security Improvements for iOS 26.3.1, iPadOS 26.3.1, macOS 26.3.1, and macOS 26.3.2. Processing maliciously crafted web content may bypass Same Origin Policy.

Is CVE-2026-20643 exploited?

• Not in the CISA KEV catalog.
• EPSS puts exploitation in the next 30 days at <1%.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2026-20643

• Apple Pushes Background WebKit Patch for Same‑Origin Bypass (2026-03-23)

Primary sources

• NVD record

What this record does not say

• No affected package data.
• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-08-11.