CVE-2026-81851: CWE-122 in WatchGuard Fireware OS
Description
CVE-2026-81851 is a heap-based buffer overflow vulnerability in the iked process of WatchGuard Fireware OS. It allows an authenticated administrator to cause a denial of service by crashing the IKE daemon through saving a specially crafted configuration. The vulnerability affects specific versions of Fireware OS. No official patch or remediation guidance is currently provided by the vendor. The CVSS 4.0 score rates this vulnerability as medium severity.
CVSS v4.0
Score 6.9medium
Affected software
WatchGuard
Fireware OS
WatchGuard
Fireware OS
WatchGuard
Fireware OS
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-81851) involves a heap-based buffer overflow in the iked process of WatchGuard Fireware OS. An authenticated administrator can exploit this flaw by saving a specially crafted configuration, which crashes the IKE daemon (iked), resulting in a denial of service condition. The flaw is categorized under CWE-122 (Heap-based Buffer Overflow). There is no vendor advisory indicating an available patch or mitigation at this time.
Potential Impact
An authenticated administrator can cause a denial of service by crashing the IKE daemon, potentially disrupting VPN or IKE-related services on the affected Fireware OS device. There is no indication of code execution or privilege escalation beyond the denial of service impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict administrative access to trusted personnel and avoid saving untrusted or unverified configurations to the iked process.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- WatchGuard
- Date Reserved
- 2026-08-27T16:29:07.182Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a916b3facd9273b49cabea8
Added to database: 08/28/2026, 11:04:31 UTC
Last enriched: 09/10/2026, 02:53:59 UTC
Last updated: 10/13/2026, 18:48:24 UTC
Views: 78
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