Vulnerability · Published Oct 27, 2026 · Assigned by WatchGuard
CVE-2026-112709Fireware OS Heap Buffer Overflow in AD Authentication Service Allows Pre-Authentication Remote Code Execution
Critical 9.2
In plain English
A critical-severity heap buffer overflow in Fireware OS from WatchGuard. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).
Severity (CVSS 4.0)9.2Critical
Exploit odds (30 days)0.4%top 63.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A heap-based buffer overflow vulnerability in the Fireware OS authentication service allows an attacker who controls or intercepts traffic to the configured Active Directory server to create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| WatchGuard | Fireware OS | 2025.1 – before 2026.412.0 – before 12.12.4 |
| WatchGuard | Fireware OS | 12.0 – before 12.5.22 |
Weakness: CWE-122, CWE-131, CWE-787 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References
- https://psirt.watchguard.com/CVE-2026-112709 vendor-advisory