CVE-2026-78011 - Vulnerability Details - OpenCVE

An integer underflow 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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Vendors	Products
Watchguard Subscribe	Fireware Os Subscribe

No data.

No data.

No data.

Advisories

No advisories yet.

Fixes

Solution

Fireware OS 2026.2.2, Fireware OS 12.12.2, Fireware OS 12.5.20

Workaround

No workaround given by the vendor.

References

Link	Providers
https://psirt.watchguard.com/CVE-2026-78011

History

Thu, 27 Aug 2026 18:00:00 +0000

Type	Values Removed	Values Added
Description		An integer underflow 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.
Title		Fireware OS Integer Underflow in Iked Allows Unauthenticated Denial of Service (DoS)
First Time appeared		Watchguard Watchguard fireware Os
Weaknesses		CWE-191 CWE-787
CPEs		cpe:2.3:a:watchguard:fireware_os::::::::
Vendors & Products		Watchguard Watchguard fireware Os
References		https://psirt.watchguard.com/CVE-2026-78011
Metrics		cvssV4_0 `{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}`

Projects

Sign in to view the affected projects.

MITRE

Status: PUBLISHED

Assigner: WatchGuard

Published: 2026-08-27T23:24:33.126Z

Updated: 2026-08-27T23:24:33.126Z

Reserved: 2026-08-21T21:46:48.681Z

Link: CVE-2026-78011

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-08-28T02:16:22.563

Modified: 2026-08-28T02:16:22.563

Link: CVE-2026-78011

Redhat

No data.

OpenCVE Enrichment

No data.

Weaknesses

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-78011", "assignerOrgId": "5d1c2695-1a31-4499-88ae-e847036fd7e3", "state": "PUBLISHED", "assignerShortName": "WatchGuard", "dateReserved": "2026-08-21T21:46:48.681Z", "datePublished": "2026-08-27T23:24:33.126Z", "dateUpdated": "2026-08-27T23:24:33.126Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "5d1c2695-1a31-4499-88ae-e847036fd7e3", "shortName": "WatchGuard", "dateUpdated": "2026-08-27T23:24:33.126Z"}, "title": "Fireware OS Integer Underflow in Iked Allows Unauthenticated Denial of Service (DoS)", "descriptions": [{"lang": "en", "value": "An integer underflow 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."}], "affected": [{"vendor": "WatchGuard", "product": "Fireware OS", "versions": [{"status": "affected", "version": "2025.0", "versionType": "custom", "lessThan": "2026.2.2"}, {"status": "affected", "version": "12.0", "versionType": "custom", "lessThan": "12.12.2"}], "defaultStatus": "unaffected", "platforms": ["Default"]}, {"vendor": "WatchGuard", "product": "Fireware OS", "versions": [{"status": "affected", "version": "12.0", "versionType": "custom", "lessThan": "12.5.20"}], "defaultStatus": "unaffected", "platforms": ["T15/T35"]}], "references": [{"url": "https://psirt.watchguard.com/CVE-2026-78011", "tags": ["vendor-advisory"]}], "cpeApplicability": [{"operator": "OR", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*", "versionStartIncluding": "12.0", "versionEndExcluding": "12.5.20"}, {"vulnerable": true, "criteria": "cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*", "versionStartIncluding": "2025.0", "versionEndExcluding": "2026.2.2"}, {"vulnerable": true, "criteria": "cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*", "versionStartIncluding": "12.0", "versionEndExcluding": "12.12.2"}]}]}], "metrics": [{"cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N", "baseScore": 8.7, "baseSeverity": "HIGH"}}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-191", "type": "CWE", "cweId": "CWE-191"}, {"lang": "en", "description": "CWE-787", "type": "CWE", "cweId": "CWE-787"}]}], "credits": [{"lang": "en", "value": "Discovered Internally by WatchGuard AI Security Research", "type": "finder"}], "configurations": [{"lang": "en", "value": "This vulnerability is exploitable on systems where a Branch Office VPN with IKEv1 is configured.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>This vulnerability is exploitable on systems where a Branch Office VPN with IKEv1 is configured.</p>"}]}], "solutions": [{"lang": "en", "value": "Fireware OS 2026.2.2, Fireware OS 12.12.2, Fireware OS 12.5.20", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Fireware OS 2026.2.2, Fireware OS 12.12.2, Fireware OS 12.5.20"}]}], "exploits": [{"lang": "en", "value": "WatchGuard is not aware of any exploitation of this vulnerability in the wild.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "WatchGuard is not aware of any exploitation of this vulnerability in the wild."}]}]}}}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "platforms": ["Default"], "product": "Fireware OS", "vendor": "WatchGuard", "versions": [{"lessThan": "2026.2.2", "status": "affected", "version": "2025.0", "versionType": "custom"}, {"lessThan": "12.12.2", "status": "affected", "version": "12.0", "versionType": "custom"}]}, {"defaultStatus": "unaffected", "platforms": ["T15/T35"], "product": "Fireware OS", "vendor": "WatchGuard", "versions": [{"lessThan": "12.5.20", "status": "affected", "version": "12.0", "versionType": "custom"}]}], "source": "5d1c2695-1a31-4499-88ae-e847036fd7e3"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "An integer underflow 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."}], "id": "CVE-2026-78011", "lastModified": "2026-08-28T02:16:22.563", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "5d1c2695-1a31-4499-88ae-e847036fd7e3", "type": "Secondary"}]}, "published": "2026-08-28T02:16:22.563", "references": [{"source": "5d1c2695-1a31-4499-88ae-e847036fd7e3", "url": "https://psirt.watchguard.com/CVE-2026-78011"}], "sourceIdentifier": "5d1c2695-1a31-4499-88ae-e847036fd7e3", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-191"}, {"lang": "en", "value": "CWE-787"}], "source": "5d1c2695-1a31-4499-88ae-e847036fd7e3", "type": "Secondary"}]}