Description
A heap-based buffer overflow vulnerability exists in the Fireware OS authentication service allows an attacker who controls or intercepts traffic to the configured Active Directory server to create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.
Published: 2026-10-27
Score: 9.2 Critical
EPSS: n/a
KEV: No
Impact: Remote Code Execution
Action: Immediate Patch
AI Analysis

Impact

A heap-based buffer overflow exists in the authentication service of WatchGuard Fireware OS, allowing an attacker who can control or intercept traffic to the configured Active Directory server to send a specially crafted response. The overflow can cause a denial of service and may enable arbitrary code execution. The flaw is rooted in improper heap memory handling (CWE-122) and buffer size mismanagement (CWE-131).

Affected Systems

The vulnerability affects WatchGuard Fireware OS, specifically versions prior to Fireware OS 2026.4, Fireware OS 12.12.4, and Fireware OS 12.5.22.

Risk and Exploitability

The CVSS score of 9.2 indicates a high severity risk. While the EPSS score is not available, the lack of a KEV listing does not diminish the threat posed by this flaw, as it enables remote exploitation in a pre-authentication phase over the network. Attackers would need to influence traffic between the Fireware instance and its AD server, a scenario that is plausible in many enterprise environments.

Generated by OpenCVE AI on October 27, 2026 at 18:54 UTC.

Remediation

Vendor Solution

Fireware OS 2026.4, Fireware OS 12.12.4, Fireware OS 12.5.22

OpenCVE Recommended Actions

  • Apply the latest Fireware OS patch (2026.4 or later, including 12.12.4 or 12.5.22 updates).
  • If upgrading is not immediately possible, isolate or block traffic between the Fireware device and the Active Directory server to prevent the crafted response from reaching the vulnerable service.
  • Implement network segmentation or firewall rules to restrict access to the AD server, ensuring only authorized systems can communicate with the Fireware device.

Generated by OpenCVE AI on October 27, 2026 at 18:54 UTC.

Tracking

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Advisories

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History

Tue, 27 Oct 2026 16:00:00 +0000

Type Values Removed Values Added
Description A heap-based buffer overflow vulnerability exists in the Fireware OS authentication service allows an attacker who controls or intercepts traffic to the configured Active Directory server to create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.
Title Fireware OS Heap Buffer Overflow in AD Authentication Service Allows Pre-Authentication Remote Code Execution
First Time appeared Watchguard
Watchguard fireware Os
Weaknesses CWE-122
CWE-131
CPEs cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*
Vendors & Products Watchguard
Watchguard fireware Os
References
Metrics cvssV4_0

{'score': 9.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

Watchguard Fireware Os
cve-icon MITRE

Status: PUBLISHED

Assigner: WatchGuard

Published:

Updated: 2026-10-27T15:52:28.053Z

Reserved: 2026-10-19T17:11:10.524Z

Link: CVE-2026-112710

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-27T16:17:30.120

Modified: 2026-10-27T16:17:30.120

Link: CVE-2026-112710

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-27T19:00:08Z

Weaknesses
  • CWE-122

    Heap-based Buffer Overflow

  • CWE-131

    Incorrect Calculation of Buffer Size