CVE-2026-13086: WatchGuard Fireware OS

Critical severity, CVSS 9.3. EPSS: 0.4% chance of exploitation in the next 30 days.

A stack-based buffer overflow in the epm (Endpoint Protection Manager) service used by the deprecated Mobile Security feature in WatchGuard Fireware OS allows an unauthenticated remote attacker to execute arbitrary code.

Affected products

• WatchGuard Fireware OS: from 2025.0, before 2026.2.2 (fixed in 2026.2.2); from 12.0, before 12.12.2 (fixed in 12.12.2); from 2026.3, before 2026.3.1 (fixed in 2026.3.1); from 12.0, before 12.5.20 (fixed in 12.5.20)

Published 2026-08-28. Last modified 2026-09-03.