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.

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