Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

What happened

Microsoft SharePoint Server on-premises contains a deserialization of untrusted data vulnerability that could allow an unauthorized attacker to execute code over a network. This vulnerability could be chained with CVE-2025-53771. CVE-2025-53770 is a patch bypass for CVE-2025-49704, and the updates for CVE-2025-53770 include more robust protection than those for CVE-2025-49704.

Affected versions

SharePoint: See original advisory Fixed: See vendor advisory.

Why it matters

This source correlation may provide earlier visibility while structured CVE metadata is still being updated.

Detection & mitigation

• Review the original advisory and validate affected versions.
• Apply vendor-provided updates or mitigations when available.