Allow Local Network Access on custom visual iframes

[Boxmodern]

A change to the Google Chrome browser is preventing our organizational custom visuals from accessing resources on our private network. This means that even images hosted on our internal network fail to load. Power BI Custom Visual iframes are missing the attribute: allow="local-network-access".  

After a recent Chrome update (version 142), Google introduced Local Network Access restrictions. Even when users enable Local Network Access for the Power BI site in Chrome, calls from custom visuals to our local network still fail.

The likely cause is that the custom visual iframes are missing the attribute: allow="local-network-access". Without this, the site permission isn’t passed through to the iframe.

Please add allow="local-network-access" to the iframes used by Power BI organizational custom visuals.

https://developer.chrome.com/blog/local-network-access

[v-sgandrathi]

Hi @Boxmodern,

Was the shared solution helpful? If so, marking it as accepted would help others resolve similar questions more quickly.

Appreciate your response.

Thank you.

[v-sgandrathi]

Hi @Boxmodern,

In addition to the previously mentioned steps, this issue is directly related to Chrome’s new enforcement approach for embedded content. Only the host application (Power BI Service / Fabric) can change iframe permissions; custom visual creators are unable to override this in their code. Microsoft needs to update their iframe sandbox settings, since the absence of the allow="local-network-access" attribute stops Chrome from passing user-granted permissions to embedded frames. Until Microsoft releases an update, organizations relying on internal network assets should keep an eye on the Microsoft 365 Roadmap and Fabric Known Issues pages, as similar browser permission changes often lead to gradual service-side updates.

Fabric Ideas - Microsoft Fabric Community

Thank you.

[Ahmed-Elfeel]

Hi @Boxmodern,

Thank you for the detailed report and you are completely right💯

So what should you do now?

• Go ahead for Microsoft Fabric support and Submit a Support Request to Microsoft Fabric
• So If you control the custom visuals code ensure all network requests use public URLs or proxy through the Power BI service.
  • Alternatively Consider hosting resources internally via a secure externally accessible endpoint (with authentication) until the fix is deployed

if this post helps, then I would appreciate a thumbs up and mark it as the solution to help the other members find it more quickly.