CVE-2026-16037 Callback Authentication Bypass via Timing Attack in PayTR's PayTR Virtual Pos iFrame API (v9x) WHMCS Module

Observable timing discrepancy vulnerability in PayTR Payment and Electronic Money Institution Inc. PayTR Virtual Pos iFrame API v9x WHMCS Module allows Black Box Reverse Engineering. This issue affects PayTR Virtual Pos iFrame API v9x WHMCS Module: from v9.0.0 before v9.0.3...