# Check browser telemetry before disabling local Application Insights authentication

> The browser JavaScript SDK has a different authentication support boundary.

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260917-164-check-browser-telemetry-before-disabling-local-application-insights-authentication/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-17T16:32:16+00:00
- Modified: 2026-09-17T16:46:29+00:00
- Last reviewed by DSE: 2026-09-17
- Resource type: Guide
- DSE priority: Information
- Topics: Cybersecurity, IT
- Reading time: 1 minutes

## What you need to know

The browser JavaScript SDK has a different authentication support boundary.

## Potentially affected

Use this review for an Application Insights resource that receives browser JavaScript telemetry as well as other application data. Identify every sending client and its instrumentation method before changing the resource's authentication policy. Do not assume that a working server-side identity validates the browser path.

## DSE recommendation

DSE recommends documenting a supported ingestion plan for each client before disabling local authentication.

## Article

## Source facts

Microsoft lists the Application Insights JavaScript SDK among the unsupported scenarios for Microsoft Entra authentication. The same guidance describes disabling local authentication so the resource accepts telemetry authenticated with managed identities or Microsoft Entra ID. Those two facts require a client-by-client migration review. [Microsoft Learn](https://learn.microsoft.com/en-us/azure/azure-monitor/app/azure-ad-authentication).

## Applicability

Use this review for an Application Insights resource that receives browser JavaScript telemetry as well as other application data. Identify every sending client and its instrumentation method before changing the resource’s authentication policy. Do not assume that a working server-side identity validates the browser path.

## DSE recommendation

DSE recommends documenting a supported ingestion plan for each client before disabling local authentication. Have the application owner explain how required browser observations will remain available. Test the complete plan in an isolated resource and retain the previous configuration. Do not add credentials to browser code to imitate a server-side authentication pattern.

## Verification

Generate approved browser and server interactions and inspect their telemetry separately in the intended test resource. Compare the client inventory with the records that arrive under the proposed authentication settings. Hold the production change if a required client has no verified supported path. Preserve the tested SDK versions and per-client results with the migration decision.

## Official references

[Microsoft Learn: Microsoft Entra Authentication for Application Insights](https://learn.microsoft.com/en-us/azure/azure-monitor/app/azure-ad-authentication).

## Primary reference

- Name: Microsoft Entra Authentication for Application Insights - Azure Monitor | Microsoft Learn
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/azure/azure-monitor/app/azure-ad-authentication
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Check browser telemetry before disabling local Application Insights authentication,” DSE Security, https://update.dsesecurity.com/updates/dse-20260917-164-check-browser-telemetry-before-disabling-local-application-insights-authentication/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
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