SecuriTricks - CVE-2026-4266

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.

Product(s) Impacted

Vendor	Product	Versions
Watchguard	Fireware Os	12.1-12.11.8, 2025.1-2026.1.2

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-502

Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	watchguard	fireware_os	12.1-12.11.8	/	/	/	/	/	/	/
a	watchguard	fireware_os	2025.1-2026.1.2	/	/	/	/	/	/	/

References

https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00007

CVSS Score

8.4 / 10

CVSS Data - 4.0

Attack Vector: LOCAL
Attack Complexity: LOW
Attack Requirements: NONE
Privileges Required: HIGH
User Interaction: NONE
Scope:
Confidentiality Impact: HIGH
Integrity Impact: HIGH
Availability Impact: HIGH
Exploit Maturity: NOT_DEFINED

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/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

View Vector String

Timeline

Published: March 30, 2026, 1:16 p.m.
Last Modified: March 30, 2026, 1:26 p.m.

Status : Awaiting Analysis

CVE has been marked for Analysis. Normally once in this state the CVE will be analyzed by NVD staff within 24 hours.

More info

Source

5d1c2695-1a31-4499-88ae-e847036fd7e3

CVE-2026-4266