CVE-2026-58644

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

Published 14 Jul 2026 · updated 17 Jul 2026 · Analyzed

9.8 Critical · CVSS 3.1, microsoft.com

Exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on 16 Jul 2026, with a remediation deadline of 19 Jul 2026 for US federal agencies.

Required action: 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.

Description

Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

References