CVE-2026-63512: Microsoft SharePoint Server Tampering Vulnerability

Overview

Severity
Medium (CVSS 6.5)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C
Category
Tampering
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Aug
Released
2026-08-11

Description

Incorrect authorization in Microsoft Office SharePoint allows an authorized attacker to perform tampering over a network.

FAQ

What could an attacker achieve by exploiting this vulnerability? An attacker could exploit this vulnerability to make unauthorized modifications to protected system data. This could allow the attacker to alter system state or configuration beyond their normal privileges. There are multiple update packages available for some of the affected software. Do I need to install all the updates listed in the Security Updates table for the software? Yes. Customers should apply all updates offered for the software installed on their systems. If multiple updates apply, they can be installed in any order. I am running SharePoint Server 2016. Do the updates for SharePoint Enterprise Server 2016 also apply to the version I am running? Yes. The same KB number applies to both SharePoint Server 2016 and SharePoint Enterprise Server 2016. Customers running either version should install the security update to be protected from this vulnerability.

Affected Products (3)

Microsoft Office

  • Microsoft SharePoint Enterprise Server 2016
  • Microsoft SharePoint Server 2019
  • Microsoft SharePoint Server Subscription Edition

Security Updates (5)

Acknowledgments

Henrique Pereira with Microsoft

Revision History

  • 2026-08-11: Information published.