sihost memory leak when exploerpatcher is installed

Author: wojcikrcCreated Aug 23, 2026Updated Aug 23, 2026

Before reporting your issue

  • I have confirmed that this issue does not happen when ExplorerPatcher is not installed
  • I do not have "register as shell extension" enabled
  • I have tried my best to check existing issues

Repro ExplorerPatcher versions

26100.8457.70.3

Repro Windows Versions

Edition Windows 11 Pro Version 25H2 Installed on ‎5/‎31/‎2025 OS build 26200.9168 Experience Windows Feature Experience Pack 1000.26100.344.0

Third-party tweak software installed

Winaero Tweaker powertoys Sysinternals

Describe the bug

sihost.exe allocates 96 GB private bytes, 2.2 TB virtual Windows System Event Log report resource exhaustion warnings Applications display "out of memory" warnings

sihost performance properties reported from process explorer:

Image

VMMAP heap 1 shows huge number of 16,384K block allocations:

Image

Expected outcome

No user action required.

Problem resolves when explorerpatcher is uninstalled.

Actual outcome

No user action required.

Problem resolves when explorerpatcher is uninstalled.

Additional info

Processor AMD Ryzen 9 9900X 12-Core Processor (4.40 GHz) Installed RAM 128 GB (126 GB usable) System type 64-bit operating system, x64-based processor Pen and touch No pen or touch input is available for this display

Crash Dumps

System doesn't crash.

Media

No response