Kiwi TCMS is an open source test management system. Prior to 16.1, the account confirmation endpoint accepted an unvalidated next parameter, allowing an unauthenticated attacker to create a URL on a trusted Kiwi TCMS hostname that redirects a victim to an arbitrary external domain. The trusted origin can support credential-harvesting pages, bypass email security filters and link-reputation checks that allowlist the organization's domain, or deliver malware through a convincing account-confirmation lure. This issue is fixed in version 16.1.