CVE-2026-8247

WatchGuard Firebox admd Out of Bounds Write Vulnerability

High 7.7 CVSS v4.0 › Published 2026-07-02Updated 2026-08-27

Summary #

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.

Product status #

ProductAffectedNot affected
Fireware OS
Default >= 2025.1, < 2026.2.1, >= 12.0, < 12.12.1, >= 11.0>= 2026.2.1, >= 12.12.1
T15/T35 >= 12.0, < 12.5.19>= 12.5.19
EUCC >= 12.0, < 12.11.9>= 12.11.9

Weakness Type and Impact #

  • CWECWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
  • CAPECCAPEC-100Overflow Buffers

Exploitation Status #

WatchGuard is not aware of any exploitation of this vulnerability in the wild.

Solution #

Fireware OS 2026.2.1, Fireware OS 12.12.1, Fireware OS 12.5.19, Fireware OS 12.11.9

References #

Credits #

  • Xander Mackenzie | @thetrueartist working with TrendAI Zero Day Initiativefinder