Microsoft's July Patch Tuesday landed this week with a heavyweight load: 117 vulnerabilities patched across the Windows ecosystem. Four of those flaws were already being exploited in the wild before release. The standout concern is the print spooler service, which keeps getting hit with out-of-band updates even after Microsoft's supposed fixes.
If you've been putting off Windows updates, now's the time to stop.
At a glance
- 117 total patches released in this month's update cycle
- Four vulnerabilities had public proof-of-concept exploits; four were already being actively exploited
- Print spooler flaw CVE-2021-34527 received out-of-band patches separate from this cycle
- Microsoft Office and Visual Studio updates are straightforward this month, requiring minimal extra testing
- No browser updates came through in this release
Why the print spooler keeps haunting Windows admins
Microsoft's print spooler service has been a recurring nightmare. CVE-2021-34527, known as PrintNightmare, first surfaced weeks ago. Microsoft issued patches, then had to patch the patches. Now another out-of-band update has arrived.
The pattern matters. When a vulnerability requires multiple fixes outside the normal release cadence, it signals the flaw is either deeply embedded in Windows architecture or that exploitation is happening at scale. Either way, treat print spooler updates as mandatory, not optional.
Microsoft's own testing guidance this month is blunt: test your printers and consider disabling spooler services you don't need. That's unusually direct advice from a vendor that usually hedges on specific actions.
Our analysis
This release exposes a core tension in Windows patching: volume doesn't equal clarity. 117 patches sound impressive until you realize the real threat sits in a service most users never think about—the background process that handles printing.
The nine critical-rated patches—all Remote Desktop flaws—compound the problem. Microsoft rarely rates that many flaws critical in a single cycle. Combined with the print spooler chaos, admins are looking at competing urgencies with limited testing windows.
For home users, the calculus is straightforward. The print spooler issue alone justifies immediate action, but the four exploited vulnerabilities make waiting genuinely risky.
Enterprise admins face harder choices. Microsoft's guidance explicitly states this month's updates involve "core system and core changes" requiring "major testing." In practice, that means staging environments need to verify printer connectivity, line-of-business application compatibility, and scripting functionality—especially anything touching JavaScript. Budget extra time this cycle.
The absence of browser updates is notable. Microsoft usually bundles Edge updates alongside Patch Tuesday. The gap suggests either a quiet month for browser flaws or a deliberate shift in how Edge receives patches. Don't assume your browser is fully patched based on this release alone.
Who should care
| User type | Priority level | Key action |
|---|---|---|
| Home users | High | Run Windows Update now; reboot and verify printing works |
| Small business admins | Critical | Patch all Windows systems immediately; test LOB applications |
| Enterprise IT | Urgent (with caveats) | Stage and test before broad deployment; verify print spooler fixes applied |
| Server administrators | Critical | Focus on CVE-2021-34458; full application testing required |
| Development teams | Low | Office and VS patches are routine this month; standard deployment |
Bottom line
Patch now. The print spooler situation demands immediate attention regardless of whether you print anything. The four exploited vulnerabilities in this cycle mean deferring updates isn't a risk tolerance decision—it's rolling dice.
Key takeaways
- Install all July patches immediately, especially out-of-band print spooler fixes
- Test printer functionality after patching; legacy line-of-business applications may break
- Consider disabling print spooler on systems that never print
- No browser updates this month doesn't mean browsers are secure—verify Edge is current through other channels
Frequently asked questions
How do I check if my Windows print spooler is vulnerable?
Microsoft released a PowerShell diagnostic tool that checks your current patch status. Run it before and after updating to confirm the fix applied correctly.
Should I disable the print spooler service entirely?
Only if your system never needs to print. You can set the service to manual or disabled in Services.msc, but some enterprise applications depend on it silently—test first.
Why did Microsoft patch the same print spooler vulnerability multiple times?
Initial fixes reportedly didn't fully address the attack surface. This happens when a flaw touches deeply integrated Windows components where fixing one path reveals another.
What's different about this month's Office and Visual Studio patches?
These updates reportedly carry minimal risk of breaking existing functionality, making them straightforward additions to your normal patching routine.
Are the four exploited vulnerabilities in this release publicly known?
Microsoft classifies some exploits as publicly disclosed but not necessarily weaponized in the wild. The distinction matters for prioritization—already-active exploitation is a faster-moving threat.