CVE-2026-56164
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
Exploited in the wild
This vulnerability is on the CISA Known Exploited Vulnerabilities list, added 2026-07-14. Federal due date: 2026-07-17.
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.
Impact
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Microsoft | Sharepoint Server | before 16.0.19725.20434 Versions 2016, 2019 |
| Microsoft | Microsoft SharePoint Enterprise Server 2016 | from 16.0.0 before 16.0.5561.1001 |
| Microsoft | Microsoft SharePoint Server 2019 | from 16.0.0 before 16.0.10417.20175 |
| Microsoft | Microsoft SharePoint Server Subscription Edition | from 16.0.0 before 16.0.19725.20434 |