Priority reviewHigh

CVE-2026-45484

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

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.

PRIORITY ASSESSMENT

FIRST EPSS indicates an elevated probability of exploitation.

Known exploitationNot established by KEV

Exploit probability35.2%

Technical severityCVSS 8.8

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.

Product: Microsoft Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition
Affected versions: >= 16.0.0 < 16.0.5556.1005, >= 16.0.0 < 16.0.10417.20153, >= 16.0.0 < 16.0.19725.20384, < 16.0.19725.20384, 2016, 2019
Fixed versions: 16.0.19725.20384

Confirm exposure before applying a vendor-supported change.

1
Identify
Confirm that Microsoft Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.