CVE-2026-3987
WatchGuard Firebox Arbitrary File Write vis Path Traversal in Fireware Web UI
Description
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.
INFO
Published Date :
April 1, 2026, 10:16 p.m.
Last Modified :
April 1, 2026, 10:16 p.m.
Remotely Exploit :
Yes !
Source :
5d1c2695-1a31-4499-88ae-e847036fd7e3
Affected Products
The following products are affected by CVE-2026-3987
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | 5d1c2695-1a31-4499-88ae-e847036fd7e3 | ||||
| CVSS 4.0 | HIGH | 5d1c2695-1a31-4499-88ae-e847036fd7e3 |
Solution
- Update Fireware OS to a patched version.
- Apply vendor security updates promptly.
- Limit privileged access to the Web UI.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-3987.
| URL | Resource |
|---|---|
| https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00009 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-3987 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-3987
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-3987 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-3987 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 5d1c2695-1a31-4499-88ae-e847036fd7e3
Apr. 01, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-22 Added Reference https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00009