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CVE-2026-4266 Details

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.

Metrics

CVSS 3.x Severity and Vector Strings:

NIST: [email protected]CVSS-B:6.7 MEDIUMVector:CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URL	Source(s)	Tag(s)
https://psirt.watchguard.com/CVE-2026-4266	WatchGuard Technologies, Inc.	Broken Link
https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00007	WatchGuard Technologies, Inc.	Vendor Advisory

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-502	Deserialization of Untrusted Data	WatchGuard Technologies, Inc.

Affected Products

Product	Versions
watchguard fireware	>= 2025.1, < 2026.2 >= 12.1, < 12.12
CPE cpe:2.3:o:watchguard:fireware:::::::: Remediation No remediation found in references.
watchguard firebox m295	All versions
CPE cpe:2.3:h:watchguard:firebox_m295:-:::::::* Remediation No remediation found in references.
watchguard firebox m395	All versions
CPE cpe:2.3:h:watchguard:firebox_m395:-:::::::* Remediation No remediation found in references.
watchguard firebox m495	All versions
CPE cpe:2.3:h:watchguard:firebox_m495:-:::::::* Remediation No remediation found in references.
watchguard firebox m595	All versions
CPE cpe:2.3:h:watchguard:firebox_m595:-:::::::* Remediation No remediation found in references.
watchguard firebox m695	All versions
CPE cpe:2.3:h:watchguard:firebox_m695:-:::::::* Remediation No remediation found in references.
watchguard firebox t115-w	All versions
CPE cpe:2.3:h:watchguard:firebox_t115-w:-:::::::* Remediation No remediation found in references.
watchguard firebox t125	All versions
CPE cpe:2.3:h:watchguard:firebox_t125:-:::::::* Remediation No remediation found in references.
watchguard firebox t125-w	All versions
CPE cpe:2.3:h:watchguard:firebox_t125-w:-:::::::* Remediation No remediation found in references.
watchguard firebox t145	All versions
CPE cpe:2.3:h:watchguard:firebox_t145:-:::::::* Remediation No remediation found in references.
watchguard firebox t145-w	All versions
CPE cpe:2.3:h:watchguard:firebox_t145-w:-:::::::* Remediation No remediation found in references.
watchguard firebox t185	All versions
CPE cpe:2.3:h:watchguard:firebox_t185:-:::::::* Remediation No remediation found in references.
watchguard firebox cloud	All versions
CPE cpe:2.3:a:watchguard:firebox_cloud:-:::::::* Remediation No remediation found in references.
watchguard firebox m270	All versions
CPE cpe:2.3:h:watchguard:firebox_m270:-:::::::* Remediation No remediation found in references.
watchguard firebox m290	All versions
CPE cpe:2.3:h:watchguard:firebox_m290:-:::::::* Remediation No remediation found in references.
watchguard firebox m370	All versions
CPE cpe:2.3:h:watchguard:firebox_m370:-:::::::* Remediation No remediation found in references.
watchguard firebox m390	All versions
CPE cpe:2.3:h:watchguard:firebox_m390:-:::::::* Remediation No remediation found in references.
watchguard firebox m440	All versions
CPE cpe:2.3:h:watchguard:firebox_m440:-:::::::* Remediation No remediation found in references.
watchguard firebox m4600	All versions
CPE cpe:2.3:h:watchguard:firebox_m4600:-:::::::* Remediation No remediation found in references.
watchguard firebox m470	All versions
CPE cpe:2.3:h:watchguard:firebox_m470:-:::::::* Remediation No remediation found in references.
watchguard firebox m4800	All versions
CPE cpe:2.3:h:watchguard:firebox_m4800:-:::::::* Remediation No remediation found in references.
watchguard firebox m5600	All versions
CPE cpe:2.3:h:watchguard:firebox_m5600:-:::::::* Remediation No remediation found in references.
watchguard firebox m570	All versions
CPE cpe:2.3:h:watchguard:firebox_m570:-:::::::* Remediation No remediation found in references.
watchguard firebox m5800	All versions
CPE cpe:2.3:h:watchguard:firebox_m5800:-:::::::* Remediation No remediation found in references.
watchguard firebox m590	All versions
CPE cpe:2.3:h:watchguard:firebox_m590:-:::::::* Remediation No remediation found in references.
watchguard firebox m670	All versions
CPE cpe:2.3:h:watchguard:firebox_m670:-:::::::* Remediation No remediation found in references.
watchguard firebox m690	All versions
CPE cpe:2.3:h:watchguard:firebox_m690:-:::::::* Remediation No remediation found in references.
watchguard firebox nv5	All versions
CPE cpe:2.3:h:watchguard:firebox_nv5:-:::::::* Remediation No remediation found in references.
watchguard firebox t20	All versions
CPE cpe:2.3:h:watchguard:firebox_t20:-:::::::* Remediation No remediation found in references.
watchguard firebox t25	All versions
CPE cpe:2.3:h:watchguard:firebox_t25:-:::::::* Remediation No remediation found in references.
watchguard firebox t40	All versions
CPE cpe:2.3:h:watchguard:firebox_t40:-:::::::* Remediation No remediation found in references.
watchguard firebox t45	All versions
CPE cpe:2.3:h:watchguard:firebox_t45:-:::::::* Remediation No remediation found in references.
watchguard firebox t55	All versions
CPE cpe:2.3:h:watchguard:firebox_t55:-:::::::* Remediation No remediation found in references.
watchguard firebox t70	All versions
CPE cpe:2.3:h:watchguard:firebox_t70:-:::::::* Remediation No remediation found in references.
watchguard firebox t80	All versions
CPE cpe:2.3:h:watchguard:firebox_t80:-:::::::* Remediation No remediation found in references.
watchguard firebox t85	All versions
CPE cpe:2.3:h:watchguard:firebox_t85:-:::::::* Remediation No remediation found in references.
watchguard fireboxv	All versions
CPE cpe:2.3:h:watchguard:fireboxv:-:::::::* Remediation No remediation found in references.

Change History

6 change records found show changes

Date	Action	Recorded By
Aug 28, 2026	CVE Modified	WatchGuard Technologies, Inc.
Aug 14, 2026	Initial Analysis	[email protected]
Aug 10, 2026	CVE Modified	WatchGuard Technologies, Inc.
Jun 17, 2026	CVE Modified	WatchGuard Technologies, Inc.
Jun 17, 2026	CVE Modified	CISA-ADP
Mar 30, 2026	New CVE Received	WatchGuard Technologies, Inc.

CVE-2026-4266 Details

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