Microsoft Patches SharePoint RCE Flaw CVE-2026-45659 Across Server Versions

Ravie LakshmananMay 26, 2026Vulnerability / Enterprise Security

Microsoft has rolled out updates to fix a remote code execution vulnerability impacting SharePoint that could be exploited by bad actors in attacks without requiring any specialized conditions to be met.

The vulnerability, tracked as CVE-2026-45659, carries a CVSS score of 8.8. It has been assigned an important severity.

"Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network," Microsoft said in an advisory released last week.

Microsoft noted that the vulnerability could be triggered by any authenticated attacker, and that it does not require administrator or other elevated privileges.

"In a network-based attack, an authenticated attacker, who has a minimum of Site Member permissions (PR:L), could execute code remotely on the SharePoint Server," the Windows maker added.

Microsoft credited a researcher named MEOW for discovering and reporting the flaw. Updates have been released for the following versions -

SharePoint Server Subscription Edition SharePoint Server 2019 SharePoint Enterprise Server 2016

Last month, Microsoft issued fixes for a spoofing vulnerability impacting Microsoft SharePoint Server (CVE-2026-32201, CVSS score: 6.5) that it said has been exploited in the wild.

Although the tech giant notes that CVE-2026-45659 is less likely to be exploited, it's essential that users apply the necessary fixes for optimal protection, particularly when considering the fact that several flaws in the collaborative platform have been repeatedly weaponized by attackers over the years.

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