Out-of-bounds Write Vulnerability in WatchGuard Fireware OS
CVE-2026-8247

7.7HIGH

Key Information:

Vendor

Watchguard

Status
Fireware Os
Vendor
CVE Published:
2 July 2026

What is CVE-2026-8247?

An out-of-bounds write vulnerability in WatchGuard Fireware OS allows an unauthenticated attacker on the same local network segment to execute arbitrary code. This poses a significant risk, as it could lead to unauthorized access and potential manipulation of the affected system, making it essential for users to apply the latest security patches and updates. The vulnerability impacts Fireware OS versions 11.0 through 11.12.4_Update1, 12.0 through 12.12, and 2025.1 through 2026.2, necessitating immediate attention to secure network environments.

Affected Version(s)

Fireware OS 11.0 <= 11.12.4+541730

Fireware OS 12.0 <= 12.12

Fireware OS 12.5 <= 12.5.18

References

https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-...
vendor-advisory

CVSS V4

Score:
7.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Xander Mackenzie | @thetrueartist working with TrendAI Zero Day Initiative
.