The Infomaniak Connect for OpenID WordPress plugin versions up to 1.0.2 contain a stored XSS vulnerability via the 'endpoint_login' parameter of the infomaniak_connect_generic_auth_url shortcode. This occurs due to improper neutralization of input during web page generation, allowing authenticated users with Contributor-level privileges or above to inject arbitrary JavaScript code. The injected scripts execute in the context of users who visit the compromised pages, potentially leading to session hijacking or other client-side attacks. The CVSS 3.1 base score is 6.4 (medium), with network attack vector, low attack complexity, privileges required, no user interaction, and impacts on confidentiality and integrity but not availability.

An authenticated attacker with Contributor-level or higher access can exploit this vulnerability to inject and store malicious scripts that execute in the browsers of users who view the affected pages. This can lead to unauthorized actions performed on behalf of users, data theft, or session compromise. The vulnerability does not affect availability and requires some level of privileges to exploit.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict Contributor-level access to trusted users only and consider removing or disabling the infomaniak_connect_generic_auth_url shortcode if feasible. Monitor plugin updates from the vendor for a security patch addressing this issue.