Description
An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user.

Note, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T15 and T35.
Published: 2026-03-30
Score: 8.4 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

Vendor Solution

Fireware OS 2026.2, Fireware OS 12.12

Tracking

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Advisories

No advisories yet.

History

Fri, 14 Aug 2026 13:45:00 +0000

Type Values Removed Values Added
First Time appeared Watchguard firebox Cloud
Watchguard firebox M270
Watchguard firebox M290
Watchguard firebox M295
Watchguard firebox M370
Watchguard firebox M390
Watchguard firebox M395
Watchguard firebox M440
Watchguard firebox M4600
Watchguard firebox M470
Watchguard firebox M4800
Watchguard firebox M495
Watchguard firebox M5600
Watchguard firebox M570
Watchguard firebox M5800
Watchguard firebox M590
Watchguard firebox M595
Watchguard firebox M670
Watchguard firebox M690
Watchguard firebox M695
Watchguard firebox Nv5
Watchguard firebox T115-w
Watchguard firebox T125
Watchguard firebox T125-w
Watchguard firebox T145
Watchguard firebox T145-w
Watchguard firebox T185
Watchguard firebox T20
Watchguard firebox T25
Watchguard firebox T40
Watchguard firebox T45
Watchguard firebox T55
Watchguard firebox T70
Watchguard firebox T80
Watchguard firebox T85
Watchguard fireboxv
Watchguard fireware
CPEs cpe:2.3:a:watchguard:firebox_cloud:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m270:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m290:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m295:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m370:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m390:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m395:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m440:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m4600:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m470:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m4800:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m495:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m5600:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m570:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m5800:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m590:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m595:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m670:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m690:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_m695:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_nv5:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t115-w:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t125-w:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t125:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t145-w:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t145:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t185:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t20:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t25:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t40:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t45:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t55:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t70:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t80:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:firebox_t85:-:*:*:*:*:*:*:*
cpe:2.3:h:watchguard:fireboxv:-:*:*:*:*:*:*:*
cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:*
Vendors & Products Watchguard firebox Cloud
Watchguard firebox M270
Watchguard firebox M290
Watchguard firebox M295
Watchguard firebox M370
Watchguard firebox M390
Watchguard firebox M395
Watchguard firebox M440
Watchguard firebox M4600
Watchguard firebox M470
Watchguard firebox M4800
Watchguard firebox M495
Watchguard firebox M5600
Watchguard firebox M570
Watchguard firebox M5800
Watchguard firebox M590
Watchguard firebox M595
Watchguard firebox M670
Watchguard firebox M690
Watchguard firebox M695
Watchguard firebox Nv5
Watchguard firebox T115-w
Watchguard firebox T125
Watchguard firebox T125-w
Watchguard firebox T145
Watchguard firebox T145-w
Watchguard firebox T185
Watchguard firebox T20
Watchguard firebox T25
Watchguard firebox T40
Watchguard firebox T45
Watchguard firebox T55
Watchguard firebox T70
Watchguard firebox T80
Watchguard firebox T85
Watchguard fireboxv
Watchguard fireware
Metrics cvssV3_1

{'score': 6.7, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}


Mon, 10 Aug 2026 17:00:00 +0000

Type Values Removed Values Added
Description An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user.This issue affects Fireware OS: 12.1 through 12.11.8 and 2025.1 through 2026.1.2. Note, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T-15 and T-35. An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user. Note, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T15 and T35.
CPEs cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:12.1
cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:2025.1
cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*
References

Mon, 30 Mar 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 30 Mar 2026 13:00:00 +0000

Type Values Removed Values Added
Description An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user.This issue affects Fireware OS: 12.1 through 12.11.8 and 2025.1 through 2026.1.2. Note, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T-15 and T-35.
Title WatchGuard Firebox Insecure Deserialization in Fireware Access Portal
First Time appeared Watchguard
Watchguard fireware Os
Weaknesses CWE-502
CPEs cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:12.1
cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:2025.1
Vendors & Products Watchguard
Watchguard fireware Os
References
Metrics cvssV4_0

{'score': 8.4, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Subscriptions

Watchguard Firebox Cloud Firebox M270 Firebox M290 Firebox M295 Firebox M370 Firebox M390 Firebox M395 Firebox M440 Firebox M4600 Firebox M470 Firebox M4800 Firebox M495 Firebox M5600 Firebox M570 Firebox M5800 Firebox M590 Firebox M595 Firebox M670 Firebox M690 Firebox M695 Firebox Nv5 Firebox T115-w Firebox T125 Firebox T125-w Firebox T145 Firebox T145-w Firebox T185 Firebox T20 Firebox T25 Firebox T40 Firebox T45 Firebox T55 Firebox T70 Firebox T80 Firebox T85 Fireboxv Fireware Fireware Os
cve-icon MITRE

Status: PUBLISHED

Assigner: WatchGuard

Published:

Updated: 2026-08-10T16:39:49.547Z

Reserved: 2026-03-16T12:50:10.806Z

Link: CVE-2026-4266

cve-icon Vulnrichment

Updated: 2026-03-30T13:19:52.252Z

cve-icon NVD

Status : Analyzed

Published: 2026-03-30T13:16:22.573

Modified: 2026-08-14T13:38:15.240

Link: CVE-2026-4266

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-11T00:00:08Z

Weaknesses