CVE-2026-66808

Microsoft SharePoint Server Remote Code Execution Vulnerability

CVSS 3.1 8.8 HIGHCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-66808

Published

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

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-66808

Published

Microsoft SharePoint Enterprise Server 2016

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Enterprise Server 2016",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.5565.1001",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                }

Microsoft SharePoint Server 2019

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Server 2019",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.10417.20198",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                }

Microsoft SharePoint Server Subscription Edition

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Server Subscription Edition",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.19725.20522",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON