Windows 11 Bug Lets Permission Log File Exceed 500GB

Microsoft has confirmed a Windows 11 bug that causes the Capability Access Manager write-ahead log file to grow continuously without being compacted, which can lead to the use of over 500GB of drive space on affected systems.

The fix is included in update KB5095093, which contains builds 26200.8737 and 26100.8737. Users can install this update through the optional updates section of Windows Update or wait for it to be included in the July 2026 Patch Tuesday rollout.

Microsoft’s release notes for KB5095093 state that the update “improves disk space usage for the CapabilityAccessManager.db-wal file.”

What Is Causing The Windows 11 Storage Bug

The Capability Access Manager is a component of Windows 11 responsible for app permissions. It controls access to privacy-sensitive features such as the camera, microphone, location, contacts, and screen capture, and logs when apps request or use these capabilities.

The issue isn’t with the permission system itself. Instead, it relates to the CapabilityAccessManager.db-wal file, which is the write-ahead log for the database. Normally, this log file grows during regular use but should be merged or compacted back into the main database.

On affected systems, however, the WAL file continues to grow without being compacted. Users have reported the file reaching sizes of about 70GB to 200GB in many cases, around 500GB in some, and approximately 513GB on one system verified through TreeSize.

How To Check If Your PC Is Affected

To determine if a system is affected by this bug, you can use one of these methods:

Method 1: Check Storage Settings: Open Settings and navigate to System, then Storage. Select Show more categories. Look at the size shown for System and reserved, or specifically for System files. If System files are showing hundreds of gigabytes, the system is likely impacted.

Method 2: Use Robocopy for Direct Verification: If System and reserved storage seem high but not excessively so, you can check the file directly. Open an elevated Command Prompt and run a command listing files in the relevant folder. This command does not copy or delete files. Look for CapabilityAccessManager.db-wal in the output.

If the file is only a few megabytes, the system is probably okay. If it is several gigabytes and continues to grow, the bug may be active.

How To Fix The Capability Access Manager Log Issue

The fix is included in KB5095093, which contains build 26200.8737 for Windows 11 25H2 and 26100.8737 for Windows 11 24H2. To install the update:

1. Open Settings
2. Go to Windows Update
3. Choose Advanced options
4. Then select Optional updates
5. Look for KB5095093 and follow the prompts to install it
6. Restart your device if needed

Users who prefer to wait can receive the update as part of the July 2026 Patch Tuesday cumulative update, which is scheduled for rollout on July 8. This version will install automatically for those with standard Windows Update settings.

After installing the fix, the WAL file should be compacted or return to its normal behavior. A system restart might be necessary for the changes to take effect.

Microsoft has confirmed the fix but has not publicly explained why some Windows 11 systems allowed the file to grow to hundreds of gigabytes in the first place.

Affected users may want to save a record of the current file size before installing the update in case Microsoft requests diagnostic data. After applying the update, monitor system storage to verify the WAL file returns to its normal size. Users can also report the issue through the Feedback Hub to help Microsoft track affected systems.

For users with SSDs, especially those with lower capacities such as 512GB or 1TB, a WAL file consuming hundreds of gigabytes can push the system dangerously low on free space. This can result in applications failing to install or update, Windows Update not completing, frequent temporary file cleanup, and backup or restore operations failing. Typical storage cleanup tools may not detect or remove the affected file, so checking for it directly is recommended.

KB5095093 is available now through the Optional Updates section of Windows Update and is expected to roll out more broadly with the July 8, 2026 Patch Tuesday cumulative update. The fix applies to Windows 11 versions 24H2 and 25H2. Microsoft has not indicated whether Windows 11 26H1 Insider builds are affected, and users on Insider channels should watch for similar fixes in upcoming flight releases. While the bug does not affect the security or core functionality of the permission system, the excessive file growth can significantly reduce available storage, and installing the update promptly is strongly recommended for anyone experiencing unexplained storage loss.