Vulnerability · Published Sep 29, 2026 · Assigned by WatchGuard
CVE-2026-86132Fireware OS Pre-Authentication Integer Underflow in iked Allows Denial of Service
High 8.2
In plain English
A high-severity security flaw 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 30% of all known vulnerabilities).
Severity (CVSS 4.0)8.2High
Exploit odds (30 days)0.4%top 69.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
An integer underflow vulnerability in the WatchGuard Fireware OS IKEv2 daemon (iked) allows a remote, unauthenticated attacker to crash the process by sending a specially crafted encrypted IKEv2 message negotiated with an AES-GCM cipher suite.
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-191 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://psirt.watchguard.com/CVE-2026-86132 vendor-advisory