CVE-2026-8247: WatchGuard Fireware

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow an unauthenticated attacker on the same local network segment to execute arbitrary code. This vulnerability affects Fireware OS 11.0 up to and including 11.12.4_Update1, 12.0 up to and including 12.12 and 2025.1 up to and including 2026.2.

Affected products

• WatchGuard Fireware: from 11.0.0, before 11.12.4 (fixed in 11.12.4); version 11.12.4 only; from 12.5, before 12.5.19 (fixed in 12.5.19); from 2025.1, before 2026.2.1 (fixed in 2026.2.1); from 12.0, before 12.12.1 (fixed in 12.12.1)

Published 2026-07-03. Last modified 2026-08-28.