WatchGuard Fireware OS iked integer underflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.5$0-$5k1.60

Summaryinfo

A vulnerability, which was classified as critical, was found in WatchGuard Fireware OS. The affected element is an unknown function of the component iked. The manipulation results in integer underflow. This vulnerability was named CVE-2026-78011. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability classified as critical has been found in WatchGuard Fireware OS (affected version not known). Affected is some unknown functionality of the component iked. The manipulation with an unknown input leads to a integer underflow vulnerability. CWE is classifying the issue as 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. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is shared for download at psirt.watchguard.com. This vulnerability is traded as CVE-2026-78011 since 08/21/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/28/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3068). Once again VulDB remains the best source for vulnerability data.

Affected

  • WatchGuard Firebox

Productinfo

Vendor

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.5

VulDB Base Score: 7.5
VulDB Temp Score: 7.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Integer underflow
CWE: CWE-191 / CWE-189
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

08/21/2026 CVE reserved
08/28/2026 +7 days Advisory disclosed
08/28/2026 +0 days VulDB entry created
08/28/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: psirt.watchguard.com
Status: Confirmed

CVE: CVE-2026-78011 (🔒)
GCVE (CVE): GCVE-0-2026-78011
GCVE (VulDB): GCVE-100-396468
CERT Bund: WID-SEC-2026-3068 - WatchGuard Firebox OS: Mehrere Schwachstellen

Entryinfo

Created: 08/28/2026 04:28
Updated: 08/28/2026 12:27
Changes: 08/28/2026 04:28 (63), 08/28/2026 12:27 (7)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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