Loading vulnerability…
CVE-2026-63520 is a remote code execution vulnerability in Microsoft SharePoint Business Connectivity Services caused by unsafe .NET type instantiation. The flaw affects supported Microsoft SharePoint versions and certain Microsoft Project Server and Microsoft Office Web Apps Server versions. By supplying crafted input that triggers unsafe object instantiation and a custom .NET gadget chain, an attacker can cause the vulnerable server to perform arbitrary operations, including execution of attacker-controlled operating system commands. In SharePoint deployments, successful exploitation results in code execution in the context of the Windows service account associated with the SharePoint site. The vulnerability has also been shown to be chainable with CVE-2026-55040, allowing unauthenticated remote code execution against vulnerable SharePoint servers.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
11 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A remote code execution vulnerability affecting Microsoft SharePoint Server.
A remote code execution vulnerability in Microsoft SharePoint Business Connectivity Services caused by unsafe .NET type instantiation, enabling attacker code execution as the SharePoint site's Windows service account.
A high-severity remote code execution vulnerability in Microsoft SharePoint's Business Connectivity Services caused by unsafe .NET type instantiation, which can allow arbitrary code execution and can be chained with CVE-2026-55040 for unauthenticated RCE.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.