CVE-2026-57105: Microsoft Office SharePoint Spoofing Vulnerability

Overview

Severity
High (CVSS 8)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Category
Spoofing
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Aug
Released
2026-08-11

Description

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to perform spoofing over a network.

FAQ

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. According to the CVSS metric, user interaction is required (UI:R) and privileges required is low (PR:L). What does that mean for this vulnerability? An authorized attacker must send the user a malicious link and convince the user to open it.

Affected Products (2)

Microsoft Office

  • Microsoft SharePoint Server 2019
  • Microsoft SharePoint Server Subscription Edition

Security Updates (3)

Acknowledgments

P1hcn

Revision History

  • 2026-08-11: Information published.