CVE-2026-3987 HIGH

CVE-2026-3987: WatchGuard Firebox Arbitrary File Write vis Path Traversal in Fireware Web UI

Vendor Watchguard
Product Fireware OS
Weakness CWE-22 · Path traversal
Published April 1, 2026
Last update April 3, 2026
View on NVD All CVEs

CVSS base score

8.6/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

A path traversal vulnerability in the Fireware OS Web UI on WatchGuard Firebox systems may allow a privileged authenticated remote attacker to execute arbitrary code in the context of an elevated system process.This issue affects Fireware OS 12.6.1 up to and including 12.11.8 and 2025.1 up to and including 2026.1.2.

Key dates

02Disclosure timeline

April 1, 2026 CVE published
April 3, 2026 Record updated