Microsoft has squashed a frustrating disk space bug that plagued Windows 11 users for months. The June 23, 2026 preview update, KB5095093, finally tackles the CapabilityAccessManager.db-wal file bloat issue—a problem that silently ate up storage on countless systems.
The culprit—the Capability Access Manager—is a background service that controls privacy permissions for hardware like cameras, microphones, and location sensors. It decides which apps get access and logs those decisions in a local database. That database, CapabilityAccessManager.db, uses Write-Ahead Logging (WAL) to maintain reliability. A sidecar file, CapabilityAccessManager.db-wal, records pending transactions and normally shrinks or is truncated after a checkpoint. But a flaw in the service’s logic allowed this file to grow unchecked, sometimes ballooning to 50GB or more.
The Unseen Storage Hog
Users first noticed the problem when disk cleanup tools reported a mysterious “other files” category that couldn’t be reclaimed. Visual disk analyzers like WinDirStat or WizTree pointed to a colossal .db-wal file deep within the ProgramData folder. The path:
C:\\ProgramData\\Microsoft\\Windows\\CapabilityAccessManager\\CapabilityAccessManager.db-wal
On forums and social media, frustrated users shared screenshots showing the file occupying 30GB, 40GB, and in extreme cases, over 70GB. For those on smaller SSDs or those running VMs with constrained disk allocations, the bloat caused system warnings, failed updates, and sluggish performance as drives neared capacity.
“I couldn’t figure out why my 256GB boot drive was constantly full until I stumbled upon this,” wrote one user on a popular Windows forum. “Storage Sense didn’t list it, Disk Cleanup didn’t see it—it was a ghost.”
The WAL file is not normally visible in standard disk cleanup because Storage Sense primarily targets temporary files, recycle bin, and updates cache. The CapabilityAccessManager database, while a legitimate system file, was simply not on Microsoft’s radar for cleanup.
The Technical Nitty-Gritty
The CapabilityAccessManager service maintains a SQLite-based database of every permission grant and denial so that Windows can quickly enforce privacy settings and manage consent prompts. When an app asks for microphone access, the service consults this database. Each query generates a transaction log entry in the WAL. Under normal conditions, a checkpoint occurs frequently, and the old WAL content is either applied to the main database or discarded.
But in the affected builds, the checkpointing mechanism seemed to stall, or the service did not properly release old log pages. Instead, the WAL file accumulated every transaction since the last system reboot or service restart. The longer the system ran, the larger the WAL grew. Some users reported that a simple restart would temporarily reset the file, but it would quickly inflate again.
A Microsoft engineer later confirmed in a developer blog that an internal race condition prevented the checkpoint thread from successfully writing back to the main database when the system was under even moderate I/O load. This caused the WAL to act as an ever-expanding buffer. Additionally, the service’s default configuration was not aggressive enough in spawning checkpoint operations after long periods of continuous logging.
How Many Users Were Hit?
While Microsoft has not shared exact numbers, telemetry from disk analysis tools and community reports suggest the bug affected a significant portion of Windows 11 installations. Systems that ran 24/7 or had frequent app permission prompts—such as those used for video conferencing—saw accelerated bloat. The issue first gained traction on Windows Insider channels in early 2026, but many production devices only began experiencing the problem after the April 2026 Patch Tuesday forced a service restart that triggered the buggy code path.
Not every system was impacted equally. Factors such as the number of registered apps, frequency of permission changes, and even driver versions for privacy-sensitive hardware contributed to the variability. This patchy nature made it harder for users to identify the root cause.
KB5095093 Delivers the Fix
The optional preview update KB5095093, released through the “Check for updates” channel with the toggle for “Get the latest updates as soon as they’re available,” includes the storage fix. According to Microsoft’s support document, the update:
- “Addresses an issue that could cause the CapabilityAccessManager database write-ahead log file (CapabilityAccessManager.db-wal) to grow excessively, potentially using all available disk space.”
- “Ensures that the service properly truncates the WAL file during checkpoints, regardless of system I/O load.”
- “Performs a one-time compaction of the database upon installing the update, which reduces the on-disk size of both the main database and its associated WAL and SHM files.”
The update also bundles other non-security improvements and fixes, but the storage bloat fix is the headline feature for anyone battling tight disk space.
How to Get the Fix
KB5095093 is a “C” week optional update—meaning it’s a preview of the fixes that will be included in the following month’s Patch Tuesday (in this case, July 2026). It is not installed automatically unless you actively seek it out:
- Open Settings > Windows Update.
- Turn on “Get the latest updates as soon as they’re available”.
- Click Check for updates.
- When KB5095093 appears, click Download & install.
After installation, you’ll need to restart your PC. The update is available for Windows 11 versions 22H2, 23H2, and 24H2 (and their enterprise equivalents). Microsoft hasn’t indicated whether the fix will be backported to Windows 10, but given the service exists there as well, it’s possible a similar update may arrive for supported Windows 10 editions.
Immediate Impact
Once installed, the system immediately truncates the WAL file to a minimal size. In tests on a virtual machine that had accumulated a 22GB WAL file, the file shrank to 8MB within seconds of logging back in after the reboot. The main database file also saw a slight reduction. The service now appears to checkpoint more aggressively, preventing future runaway growth.
For IT administrators managing fleets of machines, this update can be deployed via Windows Server Update Services (WSUS) or Microsoft Endpoint Manager using the optional update classification. It’s recommended for any environment where users report low disk space warnings and no obvious culprit.
A Note of Caution
Some tech-savvy users discovered that stopping the CapabilityAccessManager service and manually deleting the WAL file provided immediate relief even before the update arrived. However, Microsoft warns against doing this unless you understand the risks: removing the WAL while the database is in use can corrupt the main database and potentially cause the service to malfunction, leading to access denials for camera and mic. If you’re desperate and decide to do this, be sure to stop the service first, delete the file, then start it again. But with KB5095093, such manual intervention is no longer necessary.
Step-by-Step: Check Your Own System
If you suspect you’re affected but aren’t sure, follow these steps:
- Open Command Prompt as Administrator.
- Run:
cd C:\\ProgramData\\Microsoft\\Windows\\CapabilityAccessManager - Run:
dir CapabilityAccessManager.db-wal - Note the file size. If it’s larger than a few hundred MB, you’re likely hit by the bug.
Alternatively, use a disk space analyzer tool to visually inspect your drive. Look for an unusually large file in the System32 or CapabilityAccessManager directory.
A Familiar Refrain: Windows 11 Storage Woes
The CapabilityAccessManager bug is another chapter in Windows 11’s ongoing saga of unexpected disk space consumption. Over the years, users have encountered bloated Windows.old folders, clogged component stores, and runaway CBS log files. Microsoft has steadily added cleanup heuristics to Storage Sense and the Settings app, but core system service databases often fall through the cracks because they’re not classified as “temporary” files.
This update highlights the importance of preview releases. By opting into preview updates, enthusiasts and IT pros can catch such issues early and provide feedback, ultimately forcing a quicker resolution. Microsoft acknowledged that the bug had been present for at least four months before widespread reports finally surfaced in April 2026.
For Enterprise Administrators
In corporate environments, the bloat can have a cascading effect: reduced disk space leads to failed updates, which in turn can keep machines unpatched and vulnerable. Deploying KB5095093 via WSUS or Endpoint Manager is straightforward:
- Ensure your update ring includes the “Preview” or “Optional” classification.
- Target the KB5095093 update specifically to affected machines or to a pilot group.
- After deployment, monitor disk space alerts; you should see a dramatic drop in high-disk-usage incidents.
If you’re in a regulated industry where changes must be thoroughly tested, consider waiting for the July Patch Tuesday general release, which will be mandatory.
The Road Ahead
The fix will be rolled out to all Windows 11 users automatically with the July 2026 Patch Tuesday update, which will supersede KB5095093. If you can wait until July 11, you’ll get the fix along with the usual security patches without any manual action. But if your system drive is blinking red right now, the preview update is a safe bet and has few reported side effects.
Looking forward, Microsoft may need to expand its telemetry to monitor system file sizes more proactively. Services like CapabilityAccessManager, the Diagnostic Policy Service, and the State Repository Service all maintain local databases that can bloat under certain conditions. Applying consistent checkpoint management to all such components would prevent future headaches.
For now, Windows 11 users can breathe a sigh of relief—or rather, reclaim some of that precious SSD real estate. The update serves as a reminder that even the most obscure system files can have outsized impacts on everyday computing.