CVE-2026-90647ASE/Kalkitech ASE2000 V2 Communication Test Set 2.35 through 2.37 on Windows contains an improper certificate validation vulnerability in the IEC 60870-5-104 TLS client (Task Mode). This allows a network-positioned attacker to bypass certificate validation via a certificate with multiple simultaneous faults, enabling a Man-in-the-Middle attack on protected communications.