Open Redirect in github.com/AndrewBurian/powermux

Impact

Attackers may be able to craft phishing links and other open redirects by exploiting the trailing slash redirection feature. This may lead to users being redirected to untrusted sites after following an attacker crafted link.

Patches

The issue is resolved in v1.1.1

Workarounds

There are no existing workarounds.
You may detect attempts to craft urls that exploit this feature by looking for request paths containing pairs of forward slashes in sequence combined with a trailing slash e.g. https://example.com//foo/