September 2025 Patch Tuesday Preview: Key Vulnerabilities and What to Expect
As we approach the second Tuesday of the month, IT administrators and cybersecurity professionals are gearing up for another crucial cycle of security updates. The upcoming September 2025 Patch Tuesday is shaping up to be a significant one, with several critical vulnerabilities expected to be addressed across the Microsoft ecosystem and beyond. Staying ahead of these threats requires a proactive approach, and this preview will outline the key areas of concern to help you prepare your patching strategy.
Based on recent disclosures and active threat intelligence, we anticipate a moderately heavy patch load, with a particular focus on Remote Code Execution (RCE) flaws in core Windows components and enterprise applications. Here’s a breakdown of what to watch for.
Spotlight on Critical Vulnerabilities
While the full list of patches will only be confirmed on release day, several publicly disclosed or high-risk vulnerabilities are prime candidates for a fix. This month’s most pressing concerns revolve around flaws that could grant attackers complete control over affected systems with little to no user interaction.
Windows DNS Server Remote Code Execution Vulnerability: A potentially critical flaw in the Windows DNS Server role is on the radar. If confirmed, this type of vulnerability is exceptionally dangerous because it can be exploited remotely by an unauthenticated attacker. This vulnerability could be wormable, allowing malware to spread automatically between unpatched servers on a network. Systems running as domain controllers are at particularly high risk and should be prioritized for immediate patching.
Microsoft SharePoint Privilege Escalation Flaw: We are also tracking a serious privilege escalation vulnerability affecting multiple versions of Microsoft SharePoint. This flaw could allow an attacker with basic, low-level user access to elevate their permissions to that of an administrator. In a worst-case scenario, attackers could use this to access, modify, or delete sensitive company data stored on SharePoint sites. This makes it a critical patch for any organization relying on the platform for collaboration and document management.
Microsoft Edge (Chromium-based) Zero-Day Vulnerability: There are credible reports of a new zero-day vulnerability in the Chromium engine that powers Microsoft Edge. Zero-day threats are especially dangerous because they are actively being exploited by attackers before a patch is available. The flaw reportedly allows for arbitrary code execution when a user visits a specially crafted, malicious website. This vulnerability is reportedly being actively exploited in targeted attacks, making the browser update an absolute priority for all users.
Other Expected Updates
Beyond the headline-grabbing critical flaws, we expect a familiar slate of important updates across other widely used products:
- Windows Kernel: Look for several important-rated patches addressing Elevation of Privilege (EoP) vulnerabilities in the Windows Kernel. These are frequently exploited post-compromise to help attackers gain deeper system access.
- Microsoft Office: The Office suite will likely receive updates to fix RCE flaws related to the handling of malicious documents. As always, user education on phishing remains a key defense.
- .NET Framework: Expect security and quality rollups for the .NET Framework to address potential denial-of-service or information disclosure issues.
It’s also important to remember that Patch Tuesday is not exclusive to Microsoft. Be prepared for corresponding security updates from other major vendors. Organizations should anticipate critical patches for Adobe Acrobat and Reader, as well as a new security update for Google Chrome, which will likely address the same zero-day flaw affecting Microsoft Edge.
Actionable Advice and Patching Strategy
Preparation is the key to a successful and low-stress Patch Tuesday. Here are four essential steps to take now:
- Prioritize Your Assets: Identify your most critical systems. Domain controllers, public-facing web servers, and SharePoint servers should be at the top of your list. Isolate these assets and have a clear plan for patching them first.
- Test Before Deploying: Whenever possible, deploy patches to a small group of test systems or non-critical workstations first. This helps identify any potential conflicts or operational issues before a full-scale rollout impacts your entire organization.
- Verify Your Backups: Before beginning any major patching cycle, ensure you have recent, validated backups of your critical systems and data. In the unlikely event a patch causes system instability, a reliable backup is your best safety net.
- Plan for Reboots: Many critical security updates require a system reboot to take full effect. Communicate with end-users and plan for scheduled downtime to ensure patches are fully applied without causing unnecessary disruption.
September 2025 is poised to be a critical month for security hygiene. By understanding the potential threats on the horizon and preparing a methodical patching strategy, you can effectively reduce your organization’s attack surface and protect your digital assets from emerging threats. Stay vigilant and be ready to act once the patches are released.
Source: https://www.helpnetsecurity.com/2025/09/05/september-2025-patch-tuesday-forecast/
