The Aqara Cloud OAuth Authorization Endpoint (open-cn.aqara.com/oauth/authorize) suffers from improper validation of unsafe equivalence in input (CWE-1289), leading to a redirect bypass vulnerability. This allows an attacker to exploit lax domain matching controls to redirect users to unauthorized domains during the OAuth authorization process. The vulnerability is rated critical with a CVSS 3.1 score of 9.3, reflecting network attack vector, low attack complexity, no privileges required, user interaction required, scope change, and high impact on confidentiality and integrity. The affected version is =2026-04-20. There is no vendor advisory or patch information available at this time.

Successful exploitation of this vulnerability can lead to attackers redirecting users to malicious domains during OAuth authorization, potentially resulting in credential theft or unauthorized access. The vulnerability impacts confidentiality and integrity but does not affect availability. The critical CVSS score of 9.3 reflects the severity of the issue.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users and administrators should exercise caution when interacting with OAuth authorization links from Aqara Cloud and monitor for updates from the vendor. No official mitigation or workaround is currently documented.