Microsoft Warns Chromium Changes Will Break RD Web Access in Edge and Chrome

Microsoft has warned organizations that upcoming changes to Chromium-based browsers could prevent Remote Desktop Web Access (RD Web Access) from loading correctly in Windows Server.

According to MC1491832 in the Microsoft 365 Message Center, Microsoft Edge and Google Chrome will disable support for Extensible Stylesheet Language Transformations (XSLT) in mid-November 2026.

The change could prevent users from accessing remote applications and desktops through the RD Web Access portal. Microsoft has published KB5130994, outlining three workarounds administrators can implement before the deadline.

Why Chromium browsers are removing XSLT

Google says client-side XSLT accounts for approximately 0.02% of web traffic, making it a rarely used browser feature.

XSLT also relies on aging C/C++ libraries, including libxslt, which can introduce memory safety vulnerabilities. These include buffer overflows and potential arbitrary code execution.

However, Windows Server’s RD Web Access interface still depends on XSLT, meaning the browser change could disrupt organizations that use the portal.

Microsoft provides three workarounds for RD Web Access

Microsoft recommends that administrators implement one of the following solutions before Chromium browsers disable XSLT support.

Re-enable XSLT in Microsoft Edge or Chrome

Administrators can temporarily restore compatibility by enabling the XSLTEnabled browser policy through Group Policy or the Windows Registry.

For Microsoft Edge, run the following command in an elevated Command Prompt:

reg add "HKLM\SOFTWARE\Policies\Microsoft\Edge" /v XSLTEnabled /t REG_DWORD /d 1 /f

For Google Chrome, use:

reg add "HKLM\SOFTWARE\Policies\Google\Chrome" /v XSLTEnabled /t REG_DWORD /d 1 /f

After applying the policy, restart the browser and verify that RD Web Access loads correctly.

Switch to the HTML5 Remote Desktop web client

Microsoft also recommends using the HTML5 Remote Desktop web client, which provides an alternative to the affected RD Web Access interface.

Organizations that have configured the web client can access it at:

https://rdweb_server_FQDN/RDWeb/webclient/index.html

Replace rdweb_server_FQDN with the organization’s Remote Desktop server hostname.

After signing in, users can launch remote desktop sessions directly in their browser or download RDP files through Settings > Download the rdp file > OK.

Microsoft provides detailed instructions for setting up the Remote Desktop web client.

Use Microsoft Edge Internet Explorer mode

Organizations can also continue accessing RD Web Access through Microsoft Edge’s Internet Explorer mode.

To configure it, open Settings > Default browser, enable Allow sites to be reloaded in Internet Explorer mode, and add the RD Web Access URL under Internet Explorer mode pages.

Restart Edge if necessary. On the first visit, the browser may request permission to enable ActiveX functionality. Administrators can allow it when required for single sign-on with existing credentials.

The good news is that Microsoft plans to keep Internet Explorer mode available in Edge until at least 2029.

Administrators should act before mid-November

Organizations that rely on RD Web Access should test one of Microsoft’s workarounds before Chromium browsers disable XSLT support in mid-November 2026.

The HTML5 web client offers an alternative that avoids relying on the legacy XSLT functionality, while the browser policy and Internet Explorer mode provide compatibility options.

Microsoft is also preparing other Edge changes, including the retirement of legacy WAM sign-in in Edge 157. Meanwhile, the company has introduced a built-in AI troubleshooter to help users resolve Edge issues.

Via Neowin.