CVE-2026-78009
High
Description
An out-of-bounds read vulnerability in the WatchGuard Fireware OS iked process allows a remote unauthenticated attacker to create a Denial of Service (DoS) condition in VPN processing by sending specially crafted network traffic.
SeverityHigh
CVSS8.7
Exploit probability—
ProductFireware OS
PublishedAug 28, 2026
First seenAug 28, 2026
How to fix
Update
- WatchGuard Fireware OS2026.2.2, 12.12.2, 2026.3.1, 12.5.20 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| WatchGuard Fireware OS | 2025.0 ≤ v < 2026.2.2, 12.0 ≤ v < 12.12.2, 2026.3 ≤ v < 2026.3.1, 12.0 ≤ v < 12.5.20 | 2026.2.2, 12.12.2, 2026.3.1, 12.5.20 |
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