Firebox and Fireware OS
CVE-2026-81851: Fireware OS Heap-Based Buffer Overflow in iked Allows Denial of Service
A heap-based buffer overflow vulnerability in Fireware OS's iked process allows an authenticated administrator to crash the IKE daemon (iked), resulting in a denial of service, by saving a specially crafted configuration.
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 | 2026.2.1 or later |
| Fireware OS (Default) 12.0 | 12.12.1 or later |
| Fireware OS (EUCC) 12.0 | 12.11.9 or later |
| Fireware OS (T15/T35) 12.0 | 12.5.18 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A heap-based buffer overflow vulnerability in Fireware OS's iked process allows an authenticated administrator to crash the IKE daemon (iked), resulting in a denial of service, by saving a specially crafted configuration.
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.