CVE-2025-13940: WatchGuard Firebox Boot Time System Integrity Check Bypass

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-04 · updated 2026-09-25
Weakness: CWE-440

Description

An Expected Behavior Violation [CWE-440] vulnerability in WatchGuard Fireware OS may allow an attacker to bypass the Fireware OS boot time system integrity check and prevent the Firebox from shutting down in the event of a system integrity check failure. The on-demand system integrity check in the Fireware Web UI will correctly show a failed system integrity check message in the event of a failure.

Affected products

WatchGuard Fireware OS: from 2025.1 before 2025.1.3; from 12.8.1 before 12.11.5 — fixed in 12.11.5, 2025.1.3

How to fix

Upgrade to a fixed version: WatchGuard Fireware OS 12.11.5, 2025.1.3. Check the vendor advisory for mitigations.

References

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