WatchGuard Fireware OS up to 12.12.2/2026.2.2/2026.3.1 Fingerd buffer overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$0-$5k2.07-

Summaryinfo

A vulnerability, which was classified as very critical, has been found in WatchGuard Fireware OS up to 12.12.2/2026.2.2/2026.3.1. Affected is an unknown function of the component Fingerd. The manipulation leads to buffer overflow. This vulnerability is traded as CVE-2026-81433. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in WatchGuard Fireware OS up to 12.12.2/2026.2.2/2026.3.1. It has been rated as very critical. This issue affects an unknown functionality of the component Fingerd. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A stack-based buffer overflow vulnerability in WatchGuard Fireware OS's DHCP fingerprinting daemon (fingerd) allows an unauthenticated attacker with adjacent network access to execute arbitrary code or crash the process by sending a specially crafted DHCP packet.

It is possible to read the advisory at psirt.watchguard.com. The identification of this vulnerability is CVE-2026-81433 since 08/26/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/30/2026).

Upgrading to version 12.12.3, 2026.2.3 or 2026.3.2 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

Name

Version

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: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
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: Buffer overflow
CWE: CWE-120 / CWE-119
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: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Fireware OS 12.12.3/2026.2.3/2026.3.2

Timelineinfo

08/26/2026 CVE reserved
09/29/2026 +34 days VulDB entry created
09/30/2026 +0 days Advisory disclosed
09/30/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: psirt.watchguard.com
Status: Confirmed

CVE: CVE-2026-81433 (🔒)
GCVE (CVE): GCVE-0-2026-81433
GCVE (VulDB): GCVE-100-411839

Entryinfo

Created: 09/30/2026 01:36
Changes: 09/30/2026 01:36 (66)
Complete: 🔍
Cache ID: 216::103

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