CVE-2026-78011 Fireware OS Integer Underflow in Iked Allows Unauthenticated Denial of Service (DoS)
Remote unauthenticated attackers can cause a denial of service in VPN processing via crafted traffic due to an integer underflow in WatchGuard Fireware OS.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-78011?
CVE-2026-78011 is a high-severity vulnerability in WatchGuard Fireware OS, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An integer underflow 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.
Which versions are affected by CVE-2026-78011?
How do I fix CVE-2026-78011?
No fix has been published for CVE-2026-78011 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-78011 being exploited?
There is no known exploitation of CVE-2026-78011 in the wild and no public exploit code.
Sources
Also known as GHSA-3fgq-vc6q-p4hg.