Are Employees Accidentally Sharing Sensitive Files?

Article summary: Accidental file sharing happens when employees create open share links, send files to the wrong person, or move work documents into personal accounts. Safer default sharing settings, expiring links, and short, regular employee reminders make these mistakes less likely and easier to undo. 

A bookkeeper needs to send a payroll report to the company accountant. They create a sharing link, add it to an email, and hit send.

The problem? The link works for anyone who has it, and email autocomplete selected the wrong Mike.

No one meant to expose sensitive information. That’s what makes accidental file sharing so easy to miss. It often looks like normal, everyday work until a file ends up in the wrong hands.

A few simple settings and better sharing habits can prevent many of these mistakes from becoming a data security problem.

How Often Does This Actually Happen?

Accidental data loss is a common problem.

Proofpoint’s Data Loss Landscape report found that 85% of surveyed organizations experienced at least one data loss incident in the previous year. Careless users were the most common cause, including mistakes such as sending information to the wrong person or sharing sensitive files publicly.

The broader breach picture shows why employee behavior still matters. Verizon’s 2026 Data Breach Investigations Report identifies social engineering, phishing, stolen credentials, and other human-related risks alongside growing technical threats.

The takeaway is simple: employees do not have to be malicious to expose sensitive information. A wrong recipient, overly broad sharing link, or file sent through a personal account can be enough.

Four Common Ways Files Get Overshared

“Anyone With the Link” Sharing

These links can let people open a file without signing in. They make sharing easy, but they can also be forwarded to people who were never supposed to have access. Depending on your settings, the link may remain active until it expires, or someone removes it.

The Wrong Recipient

Email autocomplete makes it easy to select the wrong person. A client document intended for one contact could end up with a vendor, former employee, or someone else with a similar name. Distribution lists can make the mistake even bigger.

Personal Email and Cloud Accounts

Employees may send files to a personal email address or cloud account so they can work from home or another device. Once that happens, company data moves outside the security controls designed to protect it.

Old Shares Nobody Cleaned Up

A folder shared with a contractor or vendor years ago may still be accessible long after they need it. These forgotten permissions become even more important as AI tools gain access to company data.

Checking permissions before turning on Microsoft Copilot explains why cleaning up old access should happen before introducing AI tools that can surface information across your environment.

Settings That Prevent Mistakes

A few sharing settings can reduce accidental exposure without making everyday collaboration harder.

Microsoft 365 lets administrators control the default link type and permissions for SharePoint and OneDrive. Useful settings include:

• Making “Specific people” the default for new sharing links
• Making links view-only unless editing is necessary
• Setting expiration limits for sharing links
• Limiting external sharing when sensitive information is involved

Data loss prevention (DLP) adds another layer. Microsoft Purview DLP can identify sensitive information, such as Social Security or credit card numbers, and warn users or restrict access when a sharing action violates company policy.

The goal is not to stop employees from sharing files. It is to add safeguards that catch risky sharing before sensitive information reaches the wrong person.

Find What’s Already Out There

Changing your sharing defaults does not automatically clean up every file or link that was shared in the past. Existing access still needs to be reviewed.

Microsoft 365 provides tools for identifying externally shared files and links. Start with locations that contain sensitive information, such as payroll, financial records, or client data.

Remove access that is no longer needed and tighten permissions that are too broad. Then make sharing reviews a regular part of your security routine.

A quarterly review can help prevent forgotten links and old permissions from piling up over time.

Training That Sticks

Security settings help, but employees still make everyday decisions about where files go and who can access them. Keep training practical and focused on a few simple habits:

1. Double-check recipients before sending sensitive information.
2. Share files with specific people instead of using open links.
3. Keep work files in company-approved accounts and storage.
4. Report sharing mistakes as soon as they happen.

That last habit is especially important. If someone sends a file to the wrong person or creates the wrong sharing link, quick reporting gives IT a chance to remove access before the problem grows.

The same rules should apply to AI tools. Pasting sensitive business or client information into public AI chatbots is another form of oversharing that employees need to understand.

Is Your Business Sharing More Than It Should?

Accidental file sharing can happen quickly. One overly broad link, wrong recipient, or forgotten permission may be enough to expose sensitive information.

Unbound Digital can help you review file-sharing settings, clean up unnecessary access, and put safeguards in place that make secure sharing easier for your team.

Contact us today to schedule a free consultation. Call 423-467-7777 or reach us online.

Article FAQs

What is accidental file sharing?

Accidental file sharing happens when someone unintentionally gives the wrong person access to company information. Common examples include sending a file to the wrong recipient, using an overly broad sharing link, or moving work files to a personal account.

Are “anyone with the link” links safe to use?

These links can be useful, but they are not a good choice for sensitive files because access may not require users to sign in. When possible, share files with specific people and limit how long access lasts.

What should an employee do after sharing a file with the wrong person?

Report the mistake immediately. IT may be able to remove the sharing link, revoke access, or change the file’s permissions before the information is shared further.