# External sharing for SharePoint SHALL be limited to Existing guests or Only People in your organization
External sharing for SharePoint SHALL be limited to Existing guests or Only People in your organization.
Source: https://maester.dev/docs/tests/CISA.MS.SHAREPOINT.1.1
Part of CISA · SharePoint · External sharing · All checks
```powershell title="Run this check"
Invoke-Maester -TestId CISA.MS.SHAREPOINT.1.1
```
## Overview
External sharing for SharePoint SHALL be limited to Existing guests or Only People in your organization.
Rationale: Sharing information outside the organization via SharePoint increases the risk of unauthorized access. By limiting external sharing, administrators decrease the risk of access to information.
#### Remediation action:
1. Sign in to the [SharePoint admin center](https://go.microsoft.com/fwlink/?linkid=2185219).
2. Select Policies > Sharing.
3. Adjust external sharing slider for SharePoint to Existing guests or Only people in your organization.
> ⚠️ WARNING: This will break existing sharing.
4. Select Save.
#### Related links
* [CISA 1 External Sharing - MS.SHAREPOINT.1.1v1](https://github.com/cisagov/ScubaGear/blob/main/PowerShell/ScubaGear/baselines/sharepoint.md#mssharepoint11v1)
* [CISA ScubaGear Rego Reference](https://github.com/cisagov/ScubaGear/blob/main/PowerShell/ScubaGear/Rego/SharepointConfig.rego#L68)
## Details
Every attribute of this check
| Field | Value |
| --- | --- |
| Test ID | CISA.MS.SHAREPOINT.1.1 |
| Severity | Medium |
| Suite | CISA |
| Product | SharePoint |
| Feature | External sharing |
| Area | External access and sharing |
| Resource type | Tenant |
| User impact | High |
| Implementation cost | Medium |
| MITRE ATT&CK | T1048 Exfiltration Over Alternative Protocol, T1213.002 Sharepoint |
| Supports benchmark | CISA SCuBA Secure Configuration Baselines for Microsoft 365 (version ScubaGear main, 2026-10-11), requirement MS.SHAREPOINT.1.1 |
| Criticality | SHALL |
| Upstream requirement | MS.SHAREPOINT.1.1v1 |
| Supports controls | cisa-scuba:MS.SHAREPOINT.1.1, nist-800-53-r5:AC-2, nist-800-53-r5:AC-3, nist-800-53-r5:IA-8 |
| PowerShell test | [Test-MtCisaSpoSharing](https://github.com/maester365/maester/blob/main/tests/cisa/sharepoint/Test.CISA.MS.SHAREPOINT.1.1.ps1) |
| Services | SharePointOnline |
## Source
- Test: [`tests/cisa/sharepoint/Test.CISA.MS.SHAREPOINT.1.1.ps1`](https://github.com/maester365/maester/blob/main/tests/cisa/sharepoint/Test.CISA.MS.SHAREPOINT.1.1.ps1)
- Documentation: [`tests/cisa/sharepoint/Test.CISA.MS.SHAREPOINT.1.1.md`](https://github.com/maester365/maester/blob/main/tests/cisa/sharepoint/Test.CISA.MS.SHAREPOINT.1.1.md)
