CVE-2026-58644 · Microsoft SharePoint Server

Deserialization of untrusted data can allow remote code execution over the network on an affected SharePoint Server.

What changed

Microsoft SharePoint Enterprise Server 2016, SharePoint Server 2019 and SharePoint Server Subscription Edition. SharePoint 2016: 16.0.5556.1005 · SharePoint 2019: 16.0.10417.20153 · Subscription Edition: 16.0.19725.20384

Technical details

KB5002880 · KB5002874 · KB5002873; no separate Microsoft mitigation is listed in MSRC, so install the applicable security update immediately.

Why it matters

MSRC Exploitation Detected · confirmed by CISA KEV

Known limitations

MSRC Exploitation Detected · confirmed by CISA KEV

Now check

Install the applicable SharePoint security update immediately and investigate internet-facing farms for unauthorized access or code execution. MSRC corrected the exploitation status to Exploitation Detected on 15 July 2026.