Cross-site scripting in Microsoft SharePoint Server - CVE-2026-109504
Published: November 10, 2026
Vulnerability identifier: #VU164755
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-2026-109504
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to spoof web content and access or modify sensitive information in a victim's browser.
The vulnerability exists due to improper neutralization of input during web page generation in Microsoft SharePoint Server when rendering user-supplied content. A remote user can supply crafted content and induce a victim to interact with it to execute arbitrary script in the context of the affected site.
The Preview Pane is not an attack vector.
Affected software
Microsoft SharePoint Server
How to mitigate CVE-2026-109504
Install security update from vendor's website.
Microsoft SharePoint Server - update to 16.0.20326.20278