[Problem/Bug]: Host process crashes with EXCEPTION_ACCESS_VIOLATION_WRITE while WebView2 dismisses the virtual keyboard #5683

What happened?

Our Win32 desktop application intermittently crashes on the UI/STA thread while WebView2 is dismissing the Windows virtual keyboard.

The crash is in the host application process, not a WebView2 renderer subprocess.

Exception:
EXCEPTION_ACCESS_VIOLATION_WRITE
Invalid write address: 0xc82fb980

Relevant call stack:

combase!CCliModalLoop::HandleWakeForMsg
combase!CCliModalLoop::BlockFn
combase!ModalLoop
combase!CSyncClientCall::SendReceive2
combase!ClassicSTAThreadSendReceive
combase!CSyncClientCall::SendReceive
combase!NdrExtpProxySendReceive
RPCRT4!NdrpClientCall3
combase!ObjectStublessClient
combase!CRpcResolver::DelegateActivationToSCM
combase!CClientContextActivator::CreateInstance
combase!ICoCreateInstanceExWorker
combase!CoCreateInstance
twinapi!CInputPaneEventSource::TryHide
EmbeddedBrowserWebView!
embedded_browser_webview_current::
VirtualKeyboardDisplayManagerInputPane::DismissVirtualKeyboard
EmbeddedBrowserWebView!
embedded_browser_webview_current::
EmbeddedBrowserWebView::HideVirtualKeyboard
...
USER32!DispatchMessageWorker
OurApplication!UIMessageLoop

There is no application callback between WebView2's
HideVirtualKeyboard call and the UI message loop. WebView2 appears to initiate
CInputPaneEventSource::TryHide, after which the access violation occurs in the
COM synchronous modal loop.

Unfortunately, a full dump is not available. Could you please help determine:

1. Whether this is a known issue in WebView2 virtual-keyboard/InputPane handling.
2. Whether this signature can be correlated with Microsoft crash telemetry.
3. Whether there is a mitigation to prevent WebView2 from invoking this path.
4. Whether the issue has been fixed in a newer WebView2 Runtime or Windows update.

Additional diagnostic information

Application:

• Framework: Native Win32/C++
• Architecture: x64
• Application release: 26.3.10.381_win_x64_release
• Environment: production

WebView2 Runtime:

• Runtime version: 151.0.4129.101
• Runtime module:
  C:\Program Files (x86)\Microsoft\EdgeWebView\Application
  151.0.4129.101\EBWebView\x64\EmbeddedBrowserWebView.dll
• Architecture: x86_64
• EmbeddedBrowserWebView fault-path offsets:
  • VirtualKeyboardDisplayManagerInputPane::DismissVirtualKeyboard:
    EmbeddedBrowserWebView.dll + 0xD3484
  • EmbeddedBrowserWebView::HideVirtualKeyboard:
    EmbeddedBrowserWebView.dll + 0x93C7C
• EmbeddedBrowserWebView debug ID:
  f4ff3574-bb29-98f0-4c4c-44205044422e-1
• EmbeddedBrowserWebView code ID:
  6a86a2aa8b3000
• Microsoft symbols for EmbeddedBrowserWebView.dll were successfully resolved.

Operating system:

• Windows version reported by the application: 10.0.26200.9168
• Kernel version reported by Sentry: 10.0.26100.9168
• Architecture: x64

Selected crash event:

• Timestamp: 2026-08-24 02:36:07 UTC
• Exception: EXCEPTION_ACCESS_VIOLATION_WRITE
• Invalid write address: 0xc82fb980
• Exception mechanism: minidump
• Exception was unhandled.
• Faulting instruction:
  combase.dll + 0x332F2
  CCliModalLoop::HandleWakeForMsg
• Relevant Windows InputPane frame:
  twinapi.dll + 0x1E0AC
  CInputPaneEventSource::TryHide
• combase debug ID:
  ad7b4bc9-9152-20dd-a555-fce494c4b9c3-1
• twinapi debug ID:
  d557c65c-d8f1-55cf-6cd5-178f8ef8ca73-1

Frequency:

• The Sentry crash group contains 11 events affecting 10 users.
• First observed: 2026-06-30 18:57:00 UTC
• Most recently observed: 2026-08-27 16:02:25 UTC
• It has been observed across at least application releases
  26.2.30.370 and 26.3.10.381.

Resource state for the selected event:

• Application CPU usage: 5.47%
• Application private memory: 148 MB
• System CPU load: 79.92%
• System memory load: 69%
• Total physical memory: approximately 8 GB
• This does not appear to be an application out-of-memory condition.

Graphics information:

• GPU: Intel UHD Graphics 620
• Driver version: 30.0.101.1692

Dump and symbols:

• A 3.1 MiB minidump is available, but a full-memory dump is not available.
• Microsoft symbols for EmbeddedBrowserWebView.dll, combase.dll, and twinapi.dll
  were resolved successfully.
• Debug information for some application modules was unavailable during Sentry
  processing, so frames below the application's UI message loop may not be
  reliable.
• The minidump can potentially be provided privately upon request, but it cannot
  be attached publicly because it might contain sensitive application data.

ef449d57-4060-4c7c-b8c9-5752c40f5591.dmp

Importance

Important. My app's user experience is significantly compromised.

Runtime Channel

Stable release (WebView2 Runtime), Prerelease (Edge Canary/Dev/Beta)

Runtime Version

151.0.4129.101

SDK Version

No response

Framework

Win32

Operating System

Windows 11

OS Version

10.0.26200.9168

Repro steps

Dont know

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

Don't know

Last working version (if regression)

No response