The Planet Studio ArCa Payment Gateway versions up to 1.3.1 contain a Stored Cross-site Scripting vulnerability due to improper input neutralization during web page generation. This flaw allows attackers to inject malicious scripts that persist on the server and execute in the context of users' browsers, potentially leading to compromised user data and session integrity. The CVSS 3.1 base score is 7.1, reflecting network attack vector, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality, integrity, and availability.

Successful exploitation of this vulnerability can result in execution of arbitrary scripts in the context of affected users, leading to partial loss of confidentiality, integrity, and availability of data handled by the payment gateway. This may allow attackers to steal session tokens, manipulate transactions, or disrupt service availability to some extent.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider applying input validation and output encoding controls where possible to mitigate stored XSS risks. Monitor vendor communications for updates on patches or official mitigations.