Zen Cart 1.5.6d allows reflected XSS via the mainpage parameter to includes/templates/templatedefault/common/tplmainpage.php or includes/templates/responsiveclassic/common/tplmain_page.php.
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2020-6578.json"