ImpressCMS before 1.4.3 has Incorrect Access Control because include/findusers.php allows access by unauthenticated attackers (who are, by design, able to have a security token).
karmainsecurity.com/KIS-2022-03
seclists.org/fulldisclosure/2022/Mar/45
github.com/ImpressCMS/impresscms
github.com/ImpressCMS/impresscms/pull/967
github.com/ImpressCMS/impresscms/releases/tag/v1.4.3
hackerone.com/reports/1081137
nvd.nist.gov/vuln/detail/CVE-2021-26598
packetstormsecurity.com/files/166403/ImpressCMS-1.4.2-Incorrect-Access-Control.html