Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
MANARTECH SECURITY ALERT
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
CVE Numbers
CVE-2026-58644
Affected Product
SharePoint — Microsoft
Threat Description
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Severity Scale
CRITICALHIGHMEDIUMLOW
Severity
CRITICAL
Affected Versions
To be reviewed
Recommended Mitigation
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.