SharePoint Flaw Allows Remote Code Execution, Patched in August Update

A recent research study has highlighted a significant security vulnerability in Microsoft SharePoint, which could allow attackers to bypass built-in protections and achieve remote code execution. The issue affects multiple versions of SharePoint, including SharePoint 2013, 2016, 2019, and SharePoint Server Subscription Edition.

The vulnerability originates from the way SharePoint processes and validates markup used by web parts. A flaw in how it handles registration directives can let attackers introduce content that bypasses the platform's normal type-checking and SafeControls validation.

Microsoft has patched the issue with a fix for CVE-2026-65660, which was included in its August 11, 2026 SharePoint security updates. However, researchers caution that other code paths may still provide opportunities for attackers to explore similar bypass techniques.