This vulnerability in EverPress Mailster (<= 4.0.9) involves improper neutralization of input during web page generation, leading to a cross-site scripting (XSS) flaw. The issue allows attackers to execute arbitrary scripts in the context of the affected application, potentially impacting confidentiality, integrity, and availability. The CVSS 3.1 vector indicates the attack can be performed remotely over the network with low complexity, no privileges required, but requires user interaction. The vulnerability is confirmed published but lacks an official patch or vendor advisory detailing remediation.

Successful exploitation could allow an attacker to execute arbitrary scripts in the context of the user's browser, potentially leading to data disclosure, session hijacking, or other impacts to confidentiality, integrity, and availability. The CVSS score of 7.1 reflects these risks. However, no known exploits have been reported in the wild yet.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should exercise caution with untrusted input and consider implementing web application firewalls or input sanitization as temporary mitigations. Monitor official EverPress communications for updates.