Treat browser extensions as software with permissions, owners, and retirement

Source facts: extensions operate inside a trusted workspace

Microsoft’s enterprise guidance for managing Microsoft Edge extensions describes controls that can block extensions, allow approved extensions, or force-install required ones. Administrators can also manage extensions according to requested permissions and the websites they may access. Those controls matter because an extension can interact with browser content and behavior according to the permissions granted to it.

The same guidance recommends identifying extensions users need, preventing unwanted extensions, testing before broad deployment, and reviewing the environment periodically. A store listing or prior approval is not a permanent assurance. Publishers, packages, requested permissions, supported versions, and business needs can change after the first installation.

CISA’s Guidance for Securing Web Browsers advises organizations to manage browser add-ons and extensions as part of secure browser configuration. Together, the sources support treating extensions as governed software rather than personal decoration. They do not establish that an allowlisted extension remains safe indefinitely or that one policy fits every browser.

DSE recommendation: approve capability, not merely the extension name

Build an extension lifecycle that starts with a documented business need and ends with verified removal. The record should connect the human-readable extension name to an exact store identifier, publisher, deployment method, permission set, and accountable owner.

Establish a complete inventory. Collect extension identifiers, versions, publishers, install source, browser channel, device and user scope, installation method, requested permissions, accessible sites, last use where available, and policy status. Include side-loaded packages and extensions installed in secondary browser profiles.

Classify requested authority. Separate low-impact user-interface changes from extensions that can read page contents, change requests, access downloads, interact with native applications, or operate across all sites. Record which customer, financial, administrative, or authentication pages the extension could encounter.

Require a named purpose and owner. Document the workflow the extension enables, approved audience, support owner, data handled, alternatives considered, renewal date, and removal trigger. A popular extension without an accountable business purpose should not become an unmanaged standard.

Use layered browser policy. Begin from a controlled default, then explicitly allow or require justified extensions. Limit hosts and permissions where the browser supports it. Prevent unapproved installation paths, but preserve an exception process for legitimate work rather than encouraging users to evade management.

Test the real workflow. Validate sign-in, updates, compatibility, performance, data handling, and failure behavior in a representative group. Confirm the extension does not expose sensitive pages or break security controls. Test browser upgrades and policy removal as well as installation.

Monitor change and reassess. Watch for publisher transfers, identifier changes, new permissions, unusual update cadence, store removal, security notices, unsupported versions, and expanded site access. Route material changes back through review before continuing broad deployment.

Retire deliberately. Remove extensions when the purpose ends, the owner leaves, the product becomes unsupported, risk exceeds value, or a safer native capability replaces it. Verify removal from user and device profiles, revoke related accounts or tokens, and preserve only the evidence required by policy.

Connect the catalog to procurement and offboarding. A new extension request should expose publisher, permission, and data-handling questions before purchase, while an employee or contractor departure should trigger review of extensions, browser profiles, linked accounts, and delegated tokens. Central removal should include devices that were offline during the first policy cycle.

Factual boundary: Microsoft Edge policy names and capabilities are product- and version-specific. Other browsers and management platforms may expose different controls. An allowlist reduces unapproved installation; it does not provide continuing proof of publisher integrity, secure code, appropriate permissions, or business necessity.

Measure unmanaged extensions, high-permission approvals, records without owners, overdue reviews, permission increases, side-loaded packages, and retirement failures. The desired state is a small, explainable catalog whose authority is proportionate to its purpose and whose removal has been tested.

Official references

Microsoft Learn, Manage extensions in Microsoft Edge.

CISA, Guidance for Securing Web Browsers.