LibreOffice Macro Security Levels Explained

LibreOffice uses macro security levels to protect users from malicious embedded scripts while still enabling legitimate workflow automation. This article breaks down the four macro security levels available in LibreOffice—Very High, High, Medium, and Low—explaining how each setting behaves and which level best suits your security and operational needs.

To access these settings in LibreOffice, navigate to Tools > Options > LibreOffice > Security and click on the Macro Security button. From the Security Level tab, you can choose from the following four options:

1. Very High

• Behavior: Macros are disabled by default. Only macros located in designated trusted file locations or signed by a trusted certificate will execute.
• User Prompt: There are no warning prompts for untrusted macros; they are silently blocked from running.
• Best For: Environments that require maximum protection against unauthorized code execution, such as high-security corporate networks or systems processing untrusted external files.

2. High

• Behavior: This is the default setting in LibreOffice. Macros will only run automatically if they originate from trusted file paths or are signed by a trusted certificate.
• User Prompt: If a macro is signed by an untrusted or unrecognized certificate, LibreOffice will prompt you to confirm whether you trust the author. Unsigned macros from untrusted locations are blocked automatically without a prompt.
• Best For: Most regular users and standard business environments looking for a balance between safety and usability when working with signed scripts.

3. Medium

• Behavior: Macros are not automatically blocked, but they do not run silently either.
• User Prompt: Whenever a document containing macros is opened from an untrusted location, a confirmation dialog appears asking whether to enable or disable macros for that session.
• Best For: Developers, power users, and testing environments where unsigned or custom macros are frequently opened from varying sources and require manual case-by-case approval.

4. Low

• Behavior: All macros execute automatically upon opening a document without any verification, restriction, or notification.
• User Prompt: None.
• Best For: Isolated testing environments only. This setting is not recommended for daily use, as it leaves your system completely vulnerable to malicious macros embedded in documents.

Managing Trusted Sources

For both the High and Very High security levels, execution permissions are managed via the Trusted Sources tab inside the Macro Security dialog. Here, you can specify trusted folder paths on your local drive or network, as well as manage trusted digital certificates, allowing necessary business macros to run smoothly without lowering your overall security posture.