Medium severity · published Aug 27, 2026
CVE-2026-81851
Fireware OS Heap-Based Buffer Overflow in iked Allows Denial of Service
6.9
CVSS
0.4%
EPSS
No
On KEV
Description
A heap-based buffer overflow vulnerability in Fireware OS's iked process allows an authenticated administrator to crash the IKE daemon (iked), resulting in a denial of service, by saving a specially crafted configuration.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FO
Fireware OS · WatchGuard
2025.0 before 2026.2.1; 12.0 before 12.12.1; 12.0 before 12.11.9; 12.0 before 12.5.18 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-81851
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-81851
psirt.watchguard.com
https://psirt.watchguard.com/CVE-2026-81851
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