Redash: Open redirect vulnerability in post-login redirect handling

Redash is a package for data visualization and sharing. From 5.0.2 to 26.3.0, the get_next_path() function in Redash's authentication module stripped the scheme and netloc from user-supplied next parameters but did not normalize multiple leading slashes, allowing a crafted login URL such as /login?next=////evil.com to redirect users to an external attacker-controlled site after authentication.