Sonos api.sonos.com through 2025-04-21, when the /login/v3/oauth endpoint is used, accepts a redirect_uri containing userinfo in the authority component, which is not consistent with RFC 6819 section 5.2.3.5. An authorization code may be sent to an attacker-controlled destination. This might have further implications in conjunction with "Decompiling the app revealed a hardcoded secret."