SharePoint Flaw Under Attack After PoC Release - Patch Now

Emily Davis · 2026-07-21

If you're running Microsoft SharePoint Server, there's a critical security alert you can't afford to ignore. A third major flaw in the platform is now being actively exploited in the wild, and the clock is ticking for administrators to lock things down. This isn't just another routine update. Researchers at watchTowr have confirmed that CVE-2026-50522, a vulnerability patched by Microsoft during its July 2026 Patch Tuesday, is under active attack. The scary part? A public proof-of-concept (PoC) code is already out there, giving attackers a clear roadmap. ### What's the Big Deal? This vulnerability carries a CVSS score of 9.8, which is about as critical as it gets. It's a deserialization of untrusted data issue in Microsoft Office SharePoint. In plain English, that means an attacker can send a specially crafted request to your SharePoint server, and without any authentication, execute code remotely. We're talking full system compromise with zero user interaction. Here's what makes it especially dangerous: - **No authentication required:** The attacker doesn't need valid credentials to exploit this. - **Remote code execution:** They can run arbitrary code on the server, potentially installing malware, stealing data, or moving laterally across your network. - **Public PoC available:** Security researchers have published a working exploit, dramatically lowering the barrier for attackers. ### Who Discovered This? Microsoft credited the security team at DEVCORE for responsibly disclosing this vulnerability. They found it, reported it, and Microsoft shipped a patch in July 2026. But now that the details are public and exploits are circulating, it's a race between defenders and attackers. Think of it like this: you've been handed the keys to lock a door that's been left wide open for weeks. The question is whether you'll turn the key before someone walks in. ### What Should You Do Right Now? If you haven't already applied the July 2026 Patch Tuesday updates for SharePoint Server, stop everything and prioritize this. Here's a quick checklist: - **Verify patch status:** Check if your SharePoint servers have the update for CVE-2026-50522 installed. - **Apply the patch immediately:** If not, schedule a maintenance window as soon as possible. This isn't something you can wait on. - **Monitor for suspicious activity:** Look for unusual network traffic to your SharePoint servers, especially from unknown IPs. - **Review access logs:** Check for failed authentication attempts or unexpected file modifications. ### Why This Matters for Your Business SharePoint is often the backbone of document management and collaboration in organizations. A compromise here can expose sensitive internal documents, customer data, and intellectual property. And because attackers can execute code, they can use the server as a launching pad for deeper attacks into your network. In today's threat landscape, a single unpatched vulnerability can lead to a full-blown incident response scenario. Don't let that be you. ### The Bottom Line CVE-2026-50522 is being actively exploited. The PoC is public. The patch has been available for weeks. If you haven't applied it yet, you're essentially leaving your front door unlocked with a sign that says "come on in." Take action today. Your network—and your peace of mind—will thank you.