← WebKit Silent-Fix Report — 2026-W21

3bce213c8a  SWServer::topLevelServiceWorkerClientFromPageIdentifier() crashes when maps are out-of-sync

severity low class LogicError confidence 0.42 WebCore Service Workers
David Kilzer Wed May 20 21:27:13 2026 -0700 full: 3bce213c8ad6432cddd6b2768c54da61c1d76dc6 bug report ↗ view on GitHub ↗
Primitive: dereference of end() iterator when client maps are out-of-sync
Triage note: Replaces an ASSERT with a safe continue/return, preventing an invalid-iterator dereference crash when maps disagree.

Security-relevant, below the exploitable-grade bar for a full root-cause writeup. The triage verdict is above; the side-by-side patch is below.

Before / after

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