CVE-2019-10121: Eq-3 CCU2 Firmware

Critical severity, CVSS 9.8. EPSS: 4.6% chance of exploitation in the next 30 days.

eQ-3 HomeMatic CCU2 devices before 2.41.8 and CCU3 devices before 3.43.15 use session IDs for authentication but lack authorization checks. An attacker can obtain a session ID via the user authentication dialogue, aka HMCCU-153. This leads to automatic login as admin.

Affected products

• Eq-3 CCU2 Firmware: before 2.41.8 (fixed in 2.41.8)
• Eq-3 CCU3 Firmware: before 3.43.15 (fixed in 3.43.15)

Published 2019-07-10. Last modified 2026-06-17.