Microsoft's CSP Enforcement in SharePoint Online: What It Really Means for Your Intranet in 2026
The 60-Second Summary
Microsoft is enforcing Content Security Policy (CSP) in SharePoint Online starting March 1, 2026. This security baseline shift moves from "reporting" to "blocking" unauthorized scripts to prevent attacks like XSS. ShortPoint is proactively aligned with these modern standards, ensuring a secure and uninterrupted experience for all customers well before the deadline.
Microsoft is moving forward with full Content Security Policy (CSP) enforcement in SharePoint Online starting March 1, 2026.
If you manage a SharePoint intranet, rely on custom web parts, or use third-party solutions, this change matters—not because something is "breaking," but because the rules of what browsers will allow are getting stricter. At ShortPoint, we view this as a positive security enhancement for the ecosystem, and we are already aligned with this new direction.
CSP Enforcement Is a Security Baseline Shift
CSP is not new; browsers have supported it for years. What is changing is Microsoft's stance. Until now, SharePoint Online has largely operated in "reporting mode." This means security violations were logged but not blocked. Starting March 1, 2026, those same violations will be actively enforced.
In practical terms:
- Code that works today may be blocked tomorrow if it doesn't meet modern standards.
- Inline scripts and ad-hoc script injection patterns become security liabilities.
- Defense in Depth: CSP reduces the "blast radius" if a bug slips through.
To see exactly how these security rules protect your environment, you can view these examples of real attacks CSP helps prevent or reduce , such as Cross-Site Scripting (XSS) and Clickjacking.
Building Confidence for 2026
The move to enforcement is a signal of a maturing, secure platform. It is a forcing function to remove unsafe legacy patterns and standardize how scripts are loaded across the enterprise.
ShortPoint is aligning with SharePoint Online's CSP enforcement approach in a proactive way, so customers can continue to use ShortPoint confidently as Microsoft moves toward enforcement starting March 1, 2026.
Our architecture is engineered to follow Microsoft's recommended SPFx patterns. This ensures that our scripts load only from trusted, CSP-compliant sources, providing you with a smooth, uninterrupted experience. You can read the full breakdown of our technical roadmap here: How ShortPoint is Preparing .
The Strategic "Practice Run"
One of the most valuable aspects of the current rollout is that we are in a testing window. Because SharePoint is in Reporting Mode, you can already see exactly how enforcement will behave without impacting your users.
From a strategic perspective, readiness comes down to three questions:
- Do we know what scripts run on our pages? (Reporting mode already has this data).
- Are we relying on shortcuts? (Legacy script editors are the usual suspects).
- Are our vendors proactive? (Alignment should happen well before the deadline).
To help you navigate this period, we have outlined specific steps for what customers can do today to audit and validate their environments.
Frequently Asked Questions: SharePoint CSP Enforcement
What is the deadline for SharePoint Online CSP enforcement?
Microsoft will begin full enforcement on March 1, 2026. Until then, SharePoint remains in "Reporting Mode," where potential issues are logged but nothing is blocked.
What happens to my site once enforcement begins?
The browser will block any script or resource that does not come from a "trusted source." This includes blocking most inline scripts and unauthorized injections. Solutions that follow standard SPFx packaging will mostly be unaffected.
How can I test my pages for CSP compliance today?
You can simulate the 2026 enforcement immediately. Simply add ?csp=enforce to the end of any SharePoint page URL to see how the security rules behave in real-time.
Does this affect ShortPoint users?
ShortPoint is proactively aligning with this model well ahead of the deadline. Users can continue to use the platform confidently as we move toward full enforcement.
Next Steps for Your Team
CSP enforcement is not a last-minute fire drill; it is a long-term stability win. By understanding the shift and auditing early, you ensure your intranet remains a secure, high-performing environment.
For a comprehensive deep dive into the technical mechanics, real-world attack examples, and remediation patterns, please visit our full guide:
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