CVE-2026-78009

Deferred Deferred - Pending Action

Out-of-Bounds Read in WatchGuard Fireware OS iked Process Triggers DoS

Publication date: 2026-08-28

Last updated on: 2026-09-03

Assigner: WatchGuard Technologies, Inc.

Description

An out-of-bounds read vulnerability in the WatchGuard Fireware OS iked process allows a remote unauthenticated attacker to create a Denial of Service (DoS) condition in VPN processing by sending specially crafted network traffic.

CVSS Scores

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Meta Information

Published

2026-08-28

Last Modified

2026-09-03

Generated

2026-09-17

AI Q&A

2026-08-28

EPSS Evaluated

2026-09-15

NVD

CVE-2026-78009

EUVD

EUVD-2026-67331

Affected Vendors & Products

Vendor	Product	Version / Range
watchguard	fireware_os	From 2025.0 (inc) to 2026.2.2 (exc)
watchguard	fireware_os	From 12.0 (inc) to 12.12.2 (exc)
watchguard	fireware_os	From 2026.2.2 (inc)
watchguard	fireware_os	From 12.12.2 (inc)
watchguard	fireware_os	From 12.0 (inc) to 12.5.20 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-20	The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
CWE-125	The product reads data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

CVE-2026-78009 is an out-of-bounds read vulnerability in WatchGuard Fireware OS's iked process, which manages IKEv2 VPN connections. A remote attacker can exploit this by sending a specially crafted encrypted INFORMATIONAL message with a malformed DELETE payload during an IKEv2 SA_INIT exchange. This causes iked to read beyond allocated memory, crashing the process and disrupting VPN services. In rare cases, adjacent memory containing sensitive data like keys or certificates may be exposed.

Detection Guidance

Monitor iked process crashes or VPN service disruptions. Check logs for malformed IKEv2 INFORMATIONAL messages with DELETE payloads. Use network traffic analysis tools like tcpdump or Wireshark to inspect IKEv2 traffic for unusual patterns.

Impact Analysis

This vulnerability can cause a Denial of Service (DoS) for IKEv2 VPN services, disrupting network connectivity for users relying on VPN. If heap memory is exposed, sensitive information such as VPN keys or certificates could be leaked. The impact depends on whether the affected system is used for VPN services and if the attacker can trigger the exploit.

Compliance Impact

If this vulnerability leads to unauthorized access or exposure of sensitive data, it could violate compliance requirements under GDPR or HIPAA, which mandate protection of personal or health information. A successful exploit may result in data breaches, leading to regulatory penalties or legal consequences depending on the affected data.

Mitigation Strategies

Update Fireware OS to version 2026.2.2, 12.12.2, or 12.5.20 based on your current version. If immediate updates are not possible, restrict IKEv2 VPN access via firewall rules until patched.

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