← WebKit Silent-Fix Report — 2026-W23

e118db06408d11b659613936beccef24dea1421e  Bad IPC from WebProcess could cause UIProcess to crash in WebPermissionControllerProxy::mostReasonableWebPageProxy()

severity low class LogicError confidence 0.55 UIProcess Permissions
Chris Dumez Mon Jun 1 20:49:08 2026 -0700 full: e118db06408d11b659613936beccef24dea1421e bug report ↗ view on GitHub ↗
Primitive: Unvalidated IPC in WebPermissionControllerProxy::query crashes UIProcess
Triage note: query() called mostReasonableWebPageProxy() with no identifier for non-worker sources; a malicious WebProcess could trigger a null/invalid path and crash the UIProcess. The fix adds MESSAGE_CHECK_COMPLETION requiring an identifier unless source is SharedWorker/ServiceWorker.

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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