Ethical Hacking News
Microsoft's SharePoint Server has been identified with a critical vulnerability that enables authenticated remote code execution, forcing organizations to take immediate action to patch and protect themselves against exploitation.
Microsoft has confirmed a critical vulnerability in SharePoint Server, CVE-2026-65660, which enables authenticated remote code execution. The vulnerability affects SharePoint Server 2016, 2019, and Subscription Edition, and can be chained with another authentication bypass to reach pre-authentication remote code execution. A patch for the vulnerability was released by Microsoft on August 11, 2026, but servers that have already been patched may still be vulnerable. Organizations are advised to take immediate action to apply the patch and assess their security posture to prevent exploitation. The discovery of this vulnerability highlights the importance of prioritizing security posture and taking proactive measures to protect against emerging threats.
A recent revelation has shed light on a critical vulnerability in SharePoint Server, a widely used enterprise software solution. The vulnerability, identified as CVE-2026-65660, was initially listed as a spoofing flaw by Microsoft, but subsequent analysis by renowned researcher Dinh Ho Anh Khoa has revealed that it actually enables authenticated remote code execution. This finding has significant implications for organizations that rely on SharePoint Server for their operations, as it opens the door for unauthorized access and potential exploitation.
The vulnerability, which affects SharePoint Server 2016, 2019, and Subscription Edition, lies in the way the software checks whether server-side controls are on the SafeControls list. This filter is designed to prevent dangerous classes from loading, but due to a flaw in the ToolPane component's processing of web-part markup, an attacker can inject additional directives through unescaped quotes. This allows the attacker to register arbitrary .NET classes, which can then be used to trigger code execution through deserialization.
Khoa's research has demonstrated that the flaw can be chained with a separate, already-patched authentication bypass to reach pre-authentication remote code execution on servers configured to allow anonymous page access. This means that even if the initial vulnerability is patched, the attacker can still exploit other weaknesses to gain access to the server.
Fortunately, Microsoft has released a patch for the vulnerability, which was made available on August 11, 2026. However, it is essential for organizations to take immediate action to apply the patch and ensure that their SharePoint Server instances are protected from exploitation. Furthermore, servers that have already been patched may still be vulnerable to pre-authentication remote code execution, highlighting the need for organizations to assess their security posture and take corrective measures.
The fact that no exploitation of CVE-2026-65660 has been reported in the wild is a testament to the diligence of researchers and the swift response of organizations to security threats. Nevertheless, the discovery of this vulnerability serves as a reminder that no system is completely secure, and that the threat landscape is constantly evolving.
In light of this finding, it is essential for organizations to prioritize their security posture and take proactive measures to protect themselves against emerging threats. This may involve implementing additional security controls, conducting regular vulnerability assessments, and providing regular training to employees on cybersecurity best practices.
As the threat landscape continues to shift, it is crucial for organizations to stay vigilant and adapt their security strategies to address the evolving risks. The discovery of CVE-2026-65660 is a sobering reminder of the importance of staying informed and taking proactive measures to protect against emerging threats.
Related Information:
https://www.ethicalhackingnews.com/articles/Unveiling-the-SharePoint-Flaw-A-Critical-Vulnerability-with-Far-Reaching-Consequences-ehn.shtml
https://thehackernews.com/2026/09/sharepoint-flaw-initially-listed-as.html
Published: Tue Sep 22 07:30:01 2026 by llama3.2 3B Q4_K_M
