Microsoft has confirmed a Windows 11 bug that causes the Capabilities Access Manager write-ahead log file to continuously grow without being compacted, which can use up more than 500GB of drive space on affected systems.
This fix is included in update KB5095093, which includes 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 say that the update “improves disk space usage for the CapabilityAccessManager.db-wal file.
What Causes Windows 11 Storage Bug?
Capabilities Access Manager is a component of Windows 11 that is responsible for app permissions. It controls access to privacy-sensitive features like camera, microphone, location, contacts, and screen capture, and logs when apps request or use these capabilities.
The problem is not related to the permissions system. Instead, it belongs 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.
However, on affected systems, the WAL file continues to grow without being compressed. Users have reported that the file size has increased from around 70GB to 200GB in many cases, reaching around 500GB in some and around 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 go to System, then Storage. Select Show more categories. Look at the size shown for system and reserved, or specifically system files. If system files are showing hundreds of gigabytes, the system is likely affected.
Method 2: Use Robocopy for direct verification: If the system and reserved storage seems high but not excessive, you can check the file directly. Open an elevated command prompt and run the commands listing files in the corresponding folder. This command does not copy or delete files. See CapabilityAccessManager.db-wal in the output.
If the file is only a few megabytes, the system is probably fine. If it is several gigabytes and continues to grow, a bug may be active.
How to check if your PC is affected
The fix is included in KB5095093, which includes builds 26200.8737 for Windows 11 25H2 and 26100.8737 for Windows 11 24H2. To install updates:
- open settings
- Go to Windows Update,
- Select advanced options,
- Then select optional updates
- Look for KB5095093 and follow the prompts to install it.
- Restart your device if necessary.
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 may be necessary for the changes to take effect.
Microsoft has confirmed the fix and said that KB5095093 improves the disk space usage associated with the affected file. However, the company has not publicly explained why some Windows 11 systems initially allowed files to grow to hundreds of gigabytes.
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 you apply the update, monitor system storage to verify that the WAL file has returned to its normal size. Users can also report issues through the Feedback Hub to help Microsoft track down affected systems.
How to fix Capacity Access Manager log issue
For users with SSDs, especially those with lower capacities like 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 cause a number of problems: applications failing to install or update, Windows Update not completing due to lack of space, frequent temporary file cleanups, and backup or restore operations failing.
Users experiencing these symptoms for no apparent reason should specifically check the CapabilityAccessManager.db-wal file, as normal storage cleanup tools cannot remove it.
KB5095093 is now available through the Optional Updates section of Windows Update. It is expected to launch more widely with the July 8, 2026 Patch Tuesday cumulative update. This improvement applies to Windows 11 versions 24H2 and 25H2.
Microsoft has not indicated whether Windows 11 26H1 Insider builds are affected. Users of Insider channels should keep an eye out for similar improvements in upcoming Insider Flight releases.
If anyone notices hundreds of gigabytes of unexplained storage usage, they should install the update as soon as possible. The bug does not affect the security or core functionality of the permissions system, but the excessive file size can significantly reduce the available storage on the affected system.
