Vulnerability · Published Sep 29, 2026 · Assigned by WatchGuard
CVE-2026-86104Fireware OS Resource Exhaustion in Login Process Allows Denial of Service
High 8.7
In plain English
A high-severity uncontrolled resource consumption 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 31% of all known vulnerabilities).
Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.4%top 69.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
An uncontrolled resource consumption vulnerability in the Fireware OS login process (wgagent) allows a remote, unauthenticated attacker to cause a denial of service by sending a specially crafted request.
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 |
| WatchGuard | Fireware OS | 12.0 – before 12.5.21 |
Weakness: CWE-400, CWE-409, CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://psirt.watchguard.com/CVE-2026-86104 vendor-advisory