Stored Cross-site Scripting in results JSON API in librespeed/speedtest

librespeed/speedtest is an open source, self-hosted speed test for HTML5. In affected versions missing neutralization of the ISP information in a speedtest result leads to stored Cross-site scripting in the JSON API. The `processedString` field in the `ispinfo` parameter is missing neutralization. It is stored when a user submits a speedtest result to the telemetry API (`results/telemetry.php`) and returned in the JSON API (`results/json.php`). This vulnerability has been introduced in commit 3937b94. This vulnerability affects LibreSpeed speedtest instances running version 5.2.5 or higher which have telemetry enabled and has been addressed in version 5.3.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.