Kiwi TCMS: Open Redirect via unvalidated next parameter in account confirmation endpoint

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.