Cross-site scripting in Microsoft SharePoint Server - CVE-2026-109454
Published: November 10, 2026
Vulnerability identifier: #VU164727
CSH Severity: Low
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-109454
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary script in another user's security context, spoof content, and potentially access or modify that user's SharePoint data.
The vulnerability exists due to improper neutralization of input during web page generation in Microsoft Office SharePoint when rendering user-supplied page content. A remote user can store malicious script on a page they have permission to add or modify to execute script in another user's security context when that user views and interacts with the affected content.
The Preview Pane is not an attack vector for this vulnerability.
Affected software
Microsoft SharePoint Server
How to mitigate CVE-2026-109454
Install security update from vendor's website.
Microsoft SharePoint Server - update to 16.0.20326.20278