Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to execute code locally.

The Microsoft SharePoint Server 2019 installation on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities:

  - A remote code execution vulnerability. An attacker can     exploit this to bypass authentication and execute     unauthorized arbitrary commands. (CVE-2026-20948,     CVE-2026-62551, CVE-2026-62563)

  - A session spoofing vulnerability exists. An attacker can     exploit this to perform actions with the privileges of     another user. (CVE-2026-20958)

  - A information disclosure vulnerability exists. An     authorized attacker could use this to disclose     information over a network (CVE-2026-20959)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Microsoft SharePoint Server Subscription Edition installation on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities:

  - A remote code execution vulnerability. An attacker can     exploit this to bypass authentication and execute     unauthorized arbitrary commands. (CVE-2026-20948,     CVE-2026-62551, CVE-2026-62563)

  - A session spoofing vulnerability exists. An attacker can     exploit this to perform actions with the privileges of     another user. (CVE-2026-20958)

  - A information disclosure vulnerability exists. An     authorized attacker could use this to disclose     information over a network (CVE-2026-20959)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Microsoft SharePoint Server 2016 installation on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities:

  - A remote code execution vulnerability. An attacker can     exploit this to bypass authentication and execute     unauthorized arbitrary commands. (CVE-2026-20947,     CVE-2026-20948, CVE-2026-62551, CVE-2026-62563)

  - A session spoofing vulnerability exists. An attacker can     exploit this to perform actions with the privileges of     another user. (CVE-2026-20958)

  - A information disclosure vulnerability exists. An     authorized attacker could use this to disclose     information over a network (CVE-2026-20959)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
283475	Security Updates for Microsoft SharePoint Server 2019 (January 2026)	Nessus	Windows : Microsoft Bulletins	critical
283469	Security Updates for Microsoft SharePoint Server Subscription Edition (January 2026)	Nessus	Windows : Microsoft Bulletins	critical
283468	Security Updates for Microsoft SharePoint Server 2016 (January 2026)	Nessus	Windows : Microsoft Bulletins	critical

Detections

Analytics

CVE-2026-20951

high

Tenable Plugins

critical

critical

critical