We use optional cookies to improve your experience on our websites, such as through social media connections, and to display personalized advertising based on your online activity. If you reject optional cookies, only cookies necessary to provide you the services will be used. You may change your selection by clicking “Manage Cookies” at the bottom of the page. Privacy Statement Third-Party Cookies AcceptRejectManage cookies MSRC  Customer Guidance  Security Update Guide  Vulnerabilities  CVE-2026-56164 Microsoft SharePoint Server Elevation of Privilege Vulnerability New On this page  CVE-2026-56164  Subscribe RSS PowerShell  API  CSAF Security Vulnerability Released: Jul 14, 2026 Assigning CNA Microsoft CVE.org link CVE-2026-56164  Impact Elevation of Privilege Max Severity Moderate Weakness CWE-306: Missing Authentication for Critical Function CVSS Source Microsoft Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:F/RL:O/RC:C Metrics CVSS:3.1 5.3 / 4.9  Base score metrics: 5.3 / Temporal score metrics: 4.9  Expand all  Collapse all Metric Value   Base score metrics(8) Attack Vector Network Attack Complexity Low Privileges Required None User Interaction None Scope Unchanged Confidentiality None Integrity Low Availability None   Temporal score metrics(3) Exploit Code Maturity Functional Remediation Level Official Fix Report Confidence Confirmed Please see Common Vulnerability Scoring System for more information on the definition of these metrics. Executive Summary Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network. Exploitability The following table provides an exploitability assessment for this vulnerability at the time of original publication. Publicly disclosed No Exploited Yes Exploitability assessment Exploitation Detected Mitigations The following mitigating factors might be helpful in your situation: Enable AMSI: Ensure the Antimalware Scan Interface (AMSI) is actively integrated and scanning SharePoint and IIS worker process memory. Enable AMSI scan feature and set the Request Body Scan mode to Full in order for POST body payloads to be detected. Configure AMSI integration with SharePoint Server - https://learn.microsoft.com/en-us/sharepoint/security-for-sharepoint-server/configure-amsi-integration FAQ According to the CVSS metric, the attack vector is network (AV:N) and the attack complexity is low (AC:L). What does that mean for this vulnerability? The attack vector is Network (AV:N) because this vulnerability is remotely exploitable and can be exploited from the internet. The attack complexity is Low (AC:L) because an attacker does not require significant prior knowledge of the system and can achieve repeatable success with the payload against the vulnerable component. I am running SharePoint Server 2016. Do the updates for SharePoint Enterprise Server 2016 also apply to the version I am running? Yes. The same KB number applies to both SharePoint Server 2016 and SharePoint Enterprise Server 2016. Customers running either version should install the security update to be protected from this vulnerability. Acknowledgements Jayson Frost with Mandiant Incident Response https://cloud.google.com/security/consulting/mandiant-incident-response-services Genwei Jiang with Google Cloud, FLARE OTF https://cloud.google.com/security/mandiant Anonymous Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information. Security Updates To determine the support lifecycle for your software, see the Microsoft Support Lifecycle. Release date Descending  Edit columns  Download  Filters  Product Family  Max Severity  Impact  Platform   Clear Release date  Product Platform Impact Max Severity Article Download Build Number Assigning CNA Loading... Disclaimer The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. Revisions version revisionDate description 1.0 Jul 14, 2026 Information published.  How satisfied are you with the MSRC Security Update Guide? Rating  Broken  Bad  Below average  Average  Great!  Your Privacy Choices Consumer Health Privacy Privacy & Cookies