Why the Microsoft 365 Copilot error is important for data security

You trust your email security settings for a reason. So when an AI assistant silently reads and summarizes messages marked as confidential, that trust is shaken.

Microsoft says a bug in Microsoft 365 Copilot allowed its AI chat feature to process sensitive emails since late January.

The issue bypassed data loss prevention policies that organizations rely on to protect private information. Simply put, emails that were supposed to remain blocked were being summarized anyway.

Sign up to receive my FREE CyberGuy report

Get my best tech tips, urgent security alerts, and exclusive offers delivered right to your inbox. Plus, you’ll get instant access to my Ultimate Guide to Surviving Scams, free when you join me CYBERGUY.COM fact sheet

Microsoft 365 Copilot bug summarized sensitive emails

Microsoft says a coding error affected Microsoft 365 Copilot Chat, specifically the “work tab” feature. The AI ​​assistant helps business users summarize content, compose responses, and analyze information in Word, Excel, PowerPoint, Outlook, and OneNote.

As of January 21, an internal bug named CW1226324 caused Copilot to read and summarize emails stored in the Sent Items and Drafts folders.

The real concern is deeper. Several of those messages carried confidentiality or sensitivity labels.

Companies apply these labels along with DLP policies to prevent automated systems from accessing restricted content. Despite those safeguards, Copilot still generated summaries.

We reached out to Microsoft and a spokesperson provided CyberGuy with the following statement:

“We identified and fixed an issue where Microsoft 365 Copilot Chat could return content from emails labeled as sensitive written by a user and stored in their drafts and sent items on the Outlook desktop. This did not provide anyone with access to information they were not authorized to see. While our access controls and data protection policies remained intact, this behavior did not meet our intended Copilot experience, which is designed to exclude protected content from Copilot access. A configuration update has been implemented in all over the world for business clients.

Why the Microsoft 365 Copilot error is important for data security

Artificial intelligence tools are useful. They save time and reduce intense work. But they also depend on deep access to your data. When security measures fail, even temporarily, sensitive content can move in unexpected ways.

YOUR PHONE SHARES DATA AT NIGHT: HERE’S HOW TO STOP IT

For businesses, that could mean:

Summary Legal Discussions Outside of Planned Controls

Financial projections processed despite restrictions

HR communications are exposed to automated analysis

Even if no data leaves the organization, the bypass itself raises concerns about how AI integrates with enterprise security systems.

How Microsoft fixes the Microsoft 365 Copilot error

Microsoft says it began rolling out a fix in early February. The company continues to monitor the rollout and is reaching out to some affected users to verify that the fix is ​​working.

However, Microsoft has not provided a final timeline for the full fix. It has also not revealed how many organizations were affected.

The issue is labeled as an advisory, which generally indicates limited scope or impact. Still, many security professionals will want greater clarity before they feel comfortable.

What this Microsoft 365 Copilot issue reveals about AI security

This incident highlights something many businesses are struggling with right now. AI assistants are found within productivity platforms. They need access to email, documents, and collaboration tools to function well.

TIKTOK AFTER SALE IN THE USA: WHAT HAS CHANGED AND HOW TO USE IT SAFELY

At the same time, those platforms contain your most sensitive information. When AI capabilities expand rapidly, security policies must evolve just as quickly. Otherwise, even a small code error can lead to unexpected exposure.

Ways to stay safe after the Microsoft 365 Copilot error

If your organization uses Microsoft 365 Copilot, these are practical steps to reduce risk:

1) Review the Copilot access configuration

Work with your IT team to confirm which folders and data sources Copilot can access.

2) Revalidate DLP policies

Test sensitivity labels and DLP (Data Loss Prevention) rules to ensure they block AI processing as intended.

3) Monitor notice updates

Stay up to date on Microsoft service alerts and verify that the solution is fully deployed in your tenant.

4) Limit the scope of AI during investigations

If in doubt, consider temporarily restricting Copilot features until verification is complete.

5) Train employees on the limits of AI

Remind staff that AI assistants can process drafts and send messages. Encourage careful handling of sensitive content.

6) Audit Copilot activity logs

Review audit logs to see if Copilot accessed or summarized tagged emails. This helps determine actual exposure rather than assumed risk.

7) Review sensitivity label settings

Confirm that sensitive labels are configured to block AI processing when necessary. Misconfigured tags can create gaps even after correcting an error.

8) Reevaluate retention and write policies

Because the issue involves submitted items and drafts, evaluate whether sensitive drafts should be stored long-term or deleted after submission.

9) Limit Copilot to specific user groups

Instead of enabling Copilot across the entire organization, consider a gradual rollout to departments with lower exposure to sensitivity.

10) Conduct a post-incident security review

Take this moment to reevaluate how AI tools integrate with compliance controls. Treat it as a learning opportunity rather than a one-time problem.

Pro Tip: This Copilot error focuses on business controls. Still, AI tools work on your devices and accounts, so keeping your software up-to-date and using powerful antivirus software adds an important layer of defense. Get my picks for the best antivirus protection winners of 2026 for your Windows, Mac, Android, and iOS devices at Cyberguy.com

Considering a more private email provider

Enterprise AI failures raise a bigger question: How much access should email platforms have to your data in the first place? If you want an extra layer of privacy beyond conventional providers, privacy-focused email services are worth exploring.

Some offer end-to-end encryption, support for PGP encryption, and a strict ad-free business model that avoids scanning messages for marketing purposes.

AVAILABLE AI HELPS STROKE SURVIVORS SPEAK AGAIN

Many also allow you to create disposable email aliases, which can reduce spam and limit exposure if an address is compromised.

While no provider is immune to software errors, choosing an email service based on privacy rather than data monetization can limit the amount of information that automated systems can access in the first place.

For individuals, especially journalists and small businesses, that extra control can make a significant difference.

For recommendations on private, secure email providers that offer alias addresses, visit Cyberguy.com

Kurt’s Key Takeaways

AI assistants are becoming part of daily work life. They promise speed, efficiency and smarter workflows. But convenience should never trump safety.

This Copilot bug may have limited impact. Still, it serves as a reminder that AI tools are only as strong as the barriers behind them.

When those barriers slip, even briefly, sensitive information can move in unexpected ways. As AI becomes more integrated into enterprise software, trust will depend on transparency, quick solutions, and clear communication.

Here’s the real question: If your AI assistant can see everything you type, are you completely sure it respects all the boundaries you set? Let us know by writing to us at Cyberguy.com

CLICK HERE TO DOWNLOAD THE News APP

Sign up to receive my FREE CyberGuy report Get my best tech tips, urgent security alerts, and exclusive offers delivered right to your inbox. Plus, you’ll get instant access to my Ultimate Guide to Surviving Scams, free when you join me CYBERGUY.COM fact sheet

Copyright 2026 CyberGuy.com. All rights reserved.