authentik is an open-source identity provider. Redirect URIs in the OAuth2 provider in authentik are checked by RegEx comparison.
When no Redirect URIs are configured in a provider, authentik will automatically use the first redirect_uri value received as an allowed redirect URI, without escaping characters that have a special meaning in RegEx. Similarly, the documentation did not take this into consideration either. Given a provider with the Redirect URIs set to https://foo.example.com, an attacker can register a domain fooaexample.com, and it will correctly pass validation. authentik 2024.8.5 and 2024.10.3 fix this issue. As a workaround, When configuring OAuth2 providers, make sure to escape any wildcard characters that are not intended to function as a wildcard, for example replace `.` with `\.`.

AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CWE-185

https://github.com/goauthentik/authentik/commit/85bb638243c8d7ea42ddd3b15b3f51a90d2b8c54

https://github.com/goauthentik/authentik/security/advisories/GHSA-3q5w-6m3x-64gj