Which iOS release includes the fix for rdar://163597990 / WebKit Bug

Hi,

We're experiencing a WKWebView issue where the screen intermittently turns pure magenta (#FF00FF) in our production iOS app. After investigation, we traced this to WebKit's internal WKCompositingView.mm where [UIColor magentaColor] is used as a pending state indicator when coverView.hidden == NO.

This matches rdar://163597990 / WebKit Bug 303157 ("Magenta flash when loading page"), which was fixed in commit 303720@main on 2025-12-01 via PR #54499.

My question is simple: which iOS/Safari release includes this fix?

We're on iOS 26.3 and still seeing the issue. We need to know:

  1. Is the fix already in iOS 26.3? (If so, there may be another unfixed code path)
  2. If not, which upcoming iOS version will include it?

Our environment

  • iOS 26.3, iPhone 15 Pro Max
  • WKWebView with complex web content
  • App codebase contains zero magenta color usage — this is purely from WebKit

Related

  • rdar://163597990
  • Bug 303157 — RESOLVED FIXED
  • Bug 230531 — "Pages render as magenta after being in background"
  • PR #54499 — Merged to main 2025-12-01

Any information about the release timeline would be very helpful. Thanks!

The fix is included in iOS 26.4 seed builds. Please let us know if the problem still reproduces there.