Summary
Impact: Elevation of Privilege. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.
Details
How could an attacker exploit the vulnerability?
An authenticated attacker with access to the domain could perform remote code execution on the SharePoint server to elevate themselves to SharePoint admin.
What privileges could be gained by an attacker who successfully exploited the vulnerability?
An attacker who successfully exploited this vulnerability could gain administrator privileges.
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.
Security updates
16.0.5556.1005 — https://support.microsoft.com/help/5002880
16.0.10417.20153 — https://support.microsoft.com/help/5002874
16.0.19725.20384 — https://support.microsoft.com/help/5002873
Vulnerabilities 1
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High 8.8CVE-2026-45484 EPSS 34%
Microsoft SharePoint Elevation of Privilege Vulnerability
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.
Revision history
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#1
Information published.
References
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CVE-2026-45484 Microsoft SharePoint Elevation of Privilege Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45484
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Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
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Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
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Common Vulnerability Scoring System
https://www.first.org/cvss