Firebox and Fireware OS
CVE-2026-78010: Fireware OS Stack-Based Buffer Overflow in iked Allows Unauthenticated Denial of Service
A stack-based buffer overflow vulnerability in the WatchGuard Fireware OS iked process iallows a remote unauthenticated attacker to create a Denial of Service (DoS) condition in VPN processing by sending specially crafted network traffic.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Fireware OS (Default) 2025.0 | 2026.2.2 or later |
| Fireware OS (Default) 12.0 | 12.12.2 or later |
| Fireware OS (Default) 2026.3 | 2026.3.1 or later |
| Fireware OS (T15/T35) 12.0 | 12.5.20 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A stack-based buffer overflow vulnerability in the WatchGuard Fireware OS iked process iallows a remote unauthenticated attacker to create a Denial of Service (DoS) condition in VPN processing by sending specially crafted network traffic.
Am I affected?
This vulnerability is exploitable on systems where the Mobile VPN with IKEv2 or a Branch Office VPN with IKEv2 is configured.
Exploitation
WatchGuard is not aware of any exploitation of this vulnerability in the wild.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.