CVE-2026-4315: WatchGuard Firebox Cross-Site Request Forgery (CSRF) in Fireware Web UI

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-30 · updated 2026-08-28
Weakness: CWE-352

Description

A Cross-Site Request Forgery (CSRF) vulnerability in the WatchGuard Fireware OS WebUI could allow a remote attacker to trigger a denial-of-service (DoS) condition in the Fireware Web UI by convincing an authenticated administrator into visiting a malicious web page.

Affected products

WatchGuard Fireware OS: from 2025.1 before 2026.2; from 12.5 before 12.5.18; from 11.8 before 11.12.4; from 12.0 before 12.12; 11.12.4, 11.12.4-u1 — fixed in 11.12.4, 12.12, 12.5.18, 2026.2

How to fix

Upgrade to a fixed version: WatchGuard Fireware OS 11.12.4, 12.12, 12.5.18, 2026.2. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-4315 or the next vulnerability affects your stack