Comment by wibartle

That's me. But I don't understand your comment. Could you expand on it, either in a reply or preferably by email or via an MSRC case? You can reply with the vuln number so I can fast route it.

> The callback you're redirecting the user to at the end of that flow is forgeable

The redirect_uri is checked against the app registration. There's a general OAuth problem called "open registration redirects" that applies here, about which we've [blogged](https://www.microsoft.com/en-us/security/blog/2026/03/02/oau...) - but frankly, none of the industry solves this well.

In general, "I can create a link that goes to malware via X endpoint" isn't very interesting - you can also just create a direct link to the malware. Web browsers won't reliably show you the real destination of a link anyhow and even if they did, it's mostly just us hackers who understand URLs at all.

> as long as a way to authenticate users exists.

I'm lost. Entra supports [OpenID Connect](https://learn.microsoft.com/en-us/entra/identity-platform/v2...) for authentication. Most portals that surface admin consent authenticate the user with an OpenID Connect request either immediately before or after the admin consent request.