Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Confirm exposure before applying a vendor-supported change.
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.
Due date: 2026.07.25Confirm that Microsoft Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition and an affected version are present.
Combine exploitation signals with asset exposure and business criticality.
Follow the vendor advisory or supported update path and preserve rollback options.
Recheck the version, service health, access paths, and relevant logs.
