Microsoft is tightening how Copilot handles confidential documents after discovering a bug that affected protected content. We’ll explain why this update is changing how Microsoft’s AI interacts with your files as we sit down and sync up with your weekly technology update.

In this episode, you’ll hear more about:

• How Copilot reads business content
• What Data Loss Prevention actually does
• Why local files created a security gap
• The bug that sparked a deeper change
• How Microsoft is strengthening AI guardrails

Video Transcript

Unlike other AI assistants, Copilot works within Microsoft’s suite of applications, reading content inside your Microsoft 365 environment so it can summarize documents, draft emails, analyze spreadsheets, and generate reports. To give useful responses, most teams allow it to process information directly from Word, Excel, PowerPoint, and Outlook.

To best ensure private files aren’t used within AI, Microsoft 365 has something called Data Loss Prevention, or DLP. DLP is designed to prevent sensitive information from being shared, exposed, or processed in ways that violate company policy. If a document is labeled Confidential or Restricted, DLP can block certain actions, including whether AI tools are allowed to access it.

Until now, those protections only applied consistently to files stored in SharePoint and OneDrive, which are Microsoft’s cloud storage platforms. If a file was saved locally on someone’s computer, Copilot didn’t always enforce the same protections.

The reason comes down to how the system was built. Copilot previously checked a file’s sensitivity label by referencing it through Microsoft’s cloud infrastructure. That worked seamlessly for cloud-stored files because they have a cloud address the system could validate. Local files didn’t have that same cloud reference, so enforcement was not uniform.

At the same time, Microsoft disclosed another issue that added urgency to this change. Earlier this year, a software bug allowed Copilot Chat to summarize emails in users’ Sent Items and Drafts folders, even when those emails were labeled confidential and protected by DLP policies.

Microsoft described it as a code issue and stated that only users already authorized to view the emails could see the summaries. Still, the behavior did not align with how Copilot is supposed to treat protected content.

So now Microsoft is adjusting the architecture. Between late March and late April 2026, Microsoft is rolling out an update through an Office component that allows the Office application itself to provide the sensitivity label directly to Copilot. Instead of pulling label information only from the cloud, the system will now read it from the file at the source.

That means DLP enforcement will apply whether a document is stored in SharePoint, OneDrive, or directly on a user’s local device. If a file is labeled as restricted, Copilot will not be able to process it, regardless of where it lives.

For IT administrators, this update will automatically apply if DLP policies are already configured to block Copilot from accessing labeled content. No additional setup is required for enforcement to expand to local files. It’s also important to note that this update does not remove Copilot capabilities, it just adds more guardrails.

What this highlights is that AI governance is still evolving. Copilot is powerful because it can learn from and interact with business content, but that also means policies must be configured carefully to control what it can and cannot process.

That said, launching Copilot is not the same as governing Copilot as it evolves. In this case, sensitivity labels must be applied correctly. DLP policies must be tested. And businesses should validate that Copilot respects those controls across both cloud and local environments.

As AI continues to shift, security controls will continue to adapt alongside it. This is where a proactive IT partner can make a difference. Reviewing your Microsoft 365 configuration, validating your DLP setup, testing Copilot behavior against protected content, and ensuring policies are enforced consistently can help prevent blind spots before they become problems. If you would like help evaluating how Copilot and data protection policies are configured in your organization, contact Rocket IT using the link in this video’s description. And to stay up to date on trending technology news, hit that subscribe button and bell to catch us next week’s episode of Sync Up with Rocket IT.