CVE-2026-86132
Received Received - Intake

Integer Underflow in WatchGuard Fireware OS IKEv2 Daemon

Publication date: 2026-09-30

Last updated on: 2026-09-30

Assigner: WatchGuard Technologies, Inc.

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.

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Meta Information

Published
2026-09-30
Last Modified
2026-09-30
Generated
2026-09-30
AI Q&A
2026-09-30
EPSS Evaluated
N/A
NVD
CVE-2026-86132
EUVD
EUVD-2026-89490

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
watchguard fireware_os From 2025.0 (inc) to 2026.3.2 (inc)
watchguard fireware_os From 12.0 (inc) to 12.12.3 (inc)
watchguard fireware_os From 12.5.0 (inc) to 12.5.21 (inc)
watchguard fireware_os From 2026.2.0 (inc) to 2026.2.3 (inc)

Helpful Resources

Exploitability

CWE
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KEV
KEV Icon
CWE ID Description
CWE-191 The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

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Executive Summary

CVE-2026-86132 is an integer underflow vulnerability in WatchGuard Fireware OS's IKEv2 daemon (iked). It allows a remote, unauthenticated attacker to crash the process by sending a specially crafted encrypted IKEv2 message using an AES-GCM cipher suite.

Detection Guidance

Monitor for crashes in the IKEv2 daemon (iked) on WatchGuard Fireware OS devices. Check logs for unusual IKEv2 traffic patterns or failed connections using AES-GCM cipher suites. WatchGuard may provide detection tools or signatures in their security advisories.

Impact Analysis

This vulnerability could allow an attacker to disrupt the IKEv2 daemon, causing service outages or denial of service for VPN connections. It may also enable further attacks if combined with other vulnerabilities.

Compliance Impact

This vulnerability could potentially impact compliance with GDPR and HIPAA by enabling remote denial-of-service attacks on affected WatchGuard Fireware OS systems. A crash of the IKEv2 daemon (iked) may disrupt secure communications, leading to unauthorized access or data processing interruptions. However, no exploitation has been observed in the wild.

Mitigation Strategies

Upgrade Fireware OS to patched versions (2026.3.2, 2026.2.3, 12.12.3, 12.5.21). Disable IKEv2 if not required or restrict it to non-vulnerable cipher suites. Apply network-level mitigations like firewalls to block malicious IKEv2 traffic.

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