What Is Patch Tuesday and Why Does It Matter?
For decades, the second Tuesday of each month has been circled on the calendars of IT administrators and security professionals worldwide. This is Patch Tuesday—Microsoft’s scheduled release of security updates and patches for its ecosystem of products, ranging from Windows and Office to SQL Server, .NET, and Edge. The initiative, launched in 2003, replaced a chaotic system of sporadic updates with a predictable, manageable rhythm. As the Microsoft Security Response Center noted on its 20th anniversary, “Before this unified approach, our security updates were sporadic, posing significant challenges for IT professionals and organizations in deploying critical patches in a timely manner.”
Today, Patch Tuesday remains a cornerstone of Microsoft’s security strategy and has influenced other vendors like Adobe, which follows a similar monthly cadence. For IT teams, this predictable schedule allows for proper planning, testing, and deployment—a stark contrast to the patch-and-pray era of the early 2000s.
Recent Patch Tuesday Highlights
Below, we dive into the latest two months of updates, summarizing key vulnerabilities, affected products, and recommended actions. For a full list of previous months, check our rolling archive.
May Patch Tuesday: 139 Fixes Without Zero-Days
Microsoft’s May release delivered 139 updates across Windows, Office, .NET, and SQL Server—but notably no updates for Exchange Server. Despite the absence of actively exploited zero-days, the patch set is far from trivial. Security experts recommend a “Patch Now” stance for both Windows and Office due to several critical vulnerabilities:
- Three unauthenticated network RCEs in Netlogon, DNS Client, and the SSO Plugin for Jira and Confluence.
- Four Word Preview Pane RCEs, which could be triggered simply by previewing a malicious document.
- A large cluster of TCP/IP vulnerabilities, increasing the attack surface for network-based exploits.
- Persistent BitLocker recovery issues on Windows 10 and Windows Server (carried over from previous months).
Given this combination, an accelerated deployment schedule is warranted. For more details, visit the Microsoft Security Response Center.
April Patch Tuesday: A Record-Breaking 165 Fixes
April was one of the largest Patch Tuesday cycles in memory. Microsoft released 165 updates covering roughly 340 unique CVEs across its product line. Among these, two zero-days were patched—one of which was already being actively exploited in the wild.
The Readiness team recommends “Patch Now” schedules for nearly every major product family:
- Windows: Including fixes for the actively exploited zero-day.
- Office: Another zero-day addressed.
- Microsoft Edge (Chromium): Multiple security fixes.
- SQL Server: Several vulnerabilities resolved.
- .NET and Developer Tools: Patches for critical RCEs.
This month’s massive update highlights the ever-growing complexity of Microsoft’s software stack and the importance of staying current. IT admins should prioritize these patches, especially the actively exploited ones.
Rolling List of Recent Patch Tuesdays
To help IT professionals keep track, we maintain an updated archive of the last six months of Patch Tuesday announcements. Bookmark this page and check back each second Tuesday for the latest fixes.
Best Practices for Managing Patch Tuesday
Deploying patches effectively requires more than just clicking “install.” Follow these steps to minimize risk:
- Assess relevance: Determine which updates apply to your environment (operating systems, applications, etc.).
- Test in a staging environment: Verify that patches don’t break critical workflows.
- Prioritize critical and exploited vulnerabilities: Use Microsoft’s severity ratings and the CISA Known Exploited Vulnerabilities list.
- Schedule deployment: Use Windows Server Update Services (WSUS) or Microsoft Endpoint Configuration Manager for controlled rollouts.
- Monitor post-deployment: Watch for unexpected issues and roll back if necessary.
Conclusion
Patch Tuesday remains a vital part of the cybersecurity landscape, providing a regular, predictable cadence for patching. While the volume of updates can be daunting—especially months like April 2025 with 165 fixes—the alternative of sporadic, uncoordinated patches is far worse. By staying informed and adopting a disciplined patch management process, organizations can significantly reduce their risk.
For real-time updates, follow Computerworld’s Patch Tuesday coverage, and don’t forget to check out our archive of recent patches.