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

Published Apr 1, 2026
·
Updated

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.

Affected Software

1 affected component
WatchGuard Fireware OS>=12.6.1<=12.11.8, >=2025.1<=2026.1.2

Event History

Apr 1, 2026
CVE Published
via MITRE·09:32 PM
Data Sourced
via MITRE·09:32 PM
DescriptionWeakness
Data Sourced
via NVD·10:16 PM
DescriptionSeverityWeakness
Jul 31, 58235
Event
via FIRST·08:16 PM
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Frequently Asked Questions

1

What is the severity of CVE-2026-3987?

CVE-2026-3987 is classified as a high severity vulnerability due to its potential for arbitrary code execution.

2

How do I fix CVE-2026-3987?

To remediate CVE-2026-3987, upgrade WatchGuard Fireware OS to versions 12.11.9 or higher, or 2026.1.3 or higher.

3

Who is affected by CVE-2026-3987?

CVE-2026-3987 affects WatchGuard Firebox systems running specific versions of Fireware OS between 12.6.1 and 12.11.8 as well as versions 2025.1 up to 2026.1.2.

4

What type of attack does CVE-2026-3987 enable?

CVE-2026-3987 allows a privileged authenticated remote attacker to perform an arbitrary file write, potentially leading to remote code execution.

5

What are the potential consequences of CVE-2026-3987?

The consequences of CVE-2026-3987 can include unauthorized system access, data manipulation, and the execution of malicious code within the affected system.

Contact

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