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.
The issue was documented by Windows Latest. 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.
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 Check If Your PC Is Affected
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:
- Open Settings
- Go to Windows Update,
- Choose Advanced options,
- Then select Optional updates
- Look for KB5095093 and follow the prompts to install it.
- 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 and states that KB5095093 improves disk space usage associated with the affected file. However, the company has not publicly explained why some Windows 11 systems allowed the file to grow to hundreds of gigabytes initially.
Affected users may want to take a few steps: first, save a copy 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.
How To Fix The Capability Access Manager Log Issue
For users with SSDs, especially those with lower capacities such as 512GB or 1TB, a WAL file that takes up hundreds of gigabytes can cause the system to run dangerously low on free space.
This can lead to several issues: applications failing to install or update, Windows Update not completing due to lack of space, frequent temporary file cleanup, and backup or restore operations failing.
Users experiencing these symptoms without an obvious cause should check specifically for the CapabilityAccessManager.db-wal file, as typical storage cleanup tools may not remove it.
KB5095093 is now available through the Optional updates section of Windows Update. It is expected to be more widely rolled out 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. Users on Insider channels should watch for similar fixes in upcoming Insider flight releases.
Anyone noticing hundreds of gigabytes of unexplained storage use should install the update as soon as possible. The bug does not impact the security or core functionality of the permission system itself, but the excessive file size can significantly reduce available storage on affected systems.
