WatchGuard Firebox Arbitrary File Write vis Path Traversal in Fireware Web UI
Summary
| CVE | CVE-2026-3987 |
|---|---|
| State | PUBLISHED |
| Assigner | WatchGuard |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-01 22:16:21 UTC |
| Updated | 2026-08-14 13:30:09 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 8.6 HIGH from 5d1c2695-1a31-4499-88ae-e847036fd7e3
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/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
EPSS: 0.006380000 probability, percentile 0.473010000 (date 2026-08-11)
Problem Types: CWE-22 | CWE-22 CWE-22
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 5d1c2695-1a31-4499-88ae-e847036fd7e3 | Secondary | 8.6 | HIGH | 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/E:X/C... |
| 4.0 | CNA | DECLARED | 8.6 | HIGH | 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 |
| 3.1 | [email protected] | Primary | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
HighUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
HighUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Hardware | Watchguard | Firebox M295 | - | All | All | All |
| Hardware | Watchguard | Firebox M395 | - | All | All | All |
| Hardware | Watchguard | Firebox M495 | - | All | All | All |
| Hardware | Watchguard | Firebox M595 | - | All | All | All |
| Hardware | Watchguard | Firebox M695 | - | All | All | All |
| Hardware | Watchguard | Firebox T115-w | - | All | All | All |
| Hardware | Watchguard | Firebox T125 | - | All | All | All |
| Hardware | Watchguard | Firebox T125-w | - | All | All | All |
| Hardware | Watchguard | Firebox T145 | - | All | All | All |
| Hardware | Watchguard | Firebox T145-w | - | All | All | All |
| Hardware | Watchguard | Firebox T185 | - | All | All | All |
| Operating System | Watchguard | Fireware | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | WatchGuard | Fireware OS | affected 2025.1 2026.2 custom | Not specified |
| CNA | WatchGuard | Fireware OS | affected 12.6.1 12.12 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00009 | 5d1c2695-1a31-4499-88ae-e847036fd7e3 | www.watchguard.com | Vendor Advisory |
| psirt.watchguard.com/CVE-2026-3987 | 5d1c2695-1a31-4499-88ae-e847036fd7e3 | psirt.watchguard.com | Broken Link |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: btaol (en)
Additional Advisory Data
Solutions
CNA: Fireware OS 2026.2, Fireware OS 12.12
Exploits
CNA: WatchGuard is not aware of any exploitation of this issue in the wild.
There are currently no legacy QID mappings associated with this CVE.