HestiaCP before 1.9.5 contains a stored cross-site scripting vulnerability that allows authenticated low-privilege users to inject arbitrary HTML by creating a DNS record with a double-quote followed by a script payload in the value field. The application fails to apply htmlspecialchars() encoding to the DNS record value field rendered into the data-sort-value HTML attribute in list_dns_rec.php, allowing the payload to execute in the browser of any user who views the DNS record list, including administrators.