Vulnerability · Published Sep 29, 2026 · Assigned by WatchGuard
CVE-2026-81433Fireware OS Pre-Authentication Stack Buffer Overflow in fingerd Allows Remote Code Execution
High 8.7
In plain English
A high-severity 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 0.2% (higher than 10% of all known vulnerabilities).
Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.2%top 89.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A stack-based buffer overflow vulnerability in WatchGuard Fireware OS's DHCP fingerprinting daemon (fingerd) allows an unauthenticated attacker with adjacent network access to execute arbitrary code or crash the process by sending a specially crafted DHCP packet.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| WatchGuard | Fireware OS | 2026.3 – before 2026.3.22025.0 – before 2026.2.312.0 – before 12.12.3 |
Weakness: CWE-120, CWE-121, CWE-787 · Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References
- https://psirt.watchguard.com/CVE-2026-81433 vendor-advisory