Fortinet FortiClient Heap overflow in kernel driver due to missing size validation (FG-IR-26-156)

high Nessus Plugin ID 336074

Synopsis

remote Windows host is missing one or more security-related updates.

Description

The version of FortiClient installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the FG-IR-26-156 advisory.

- A buffer copy without checking size of input ('classic buffer overflow') vulnerability in Fortinet FortiClientWindows 7.4.0 through 7.4.3, FortiClientWindows 7.2.0 through 7.2.11 may allow an unauthenticated attacker in a position to alter or craft DNS responses to the targeted host to execute arbitrary code via malicious packets. (CVE-2026-70465)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

For 7.2.x, upgrade to FortiClient version 7.2.12 or later. For 7.4.x, upgrade to FortiClient version 7.4.4 or later.

Plugin Details

Severity: High

ID: 336074

File Name: forticlient_FG-IR-26-156.nasl

Version: 1.1

Type: Local

Agent: windows

Family: Windows

Published: 8/17/2026

Updated: 8/17/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.76

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 5.6

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-70465

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:fortinet:forticlient

Required KB Items: Settings/ParanoidReport, installed_sw/FortiClient

Exploit Ease: No known exploits are available

Patch Publication Date: 8/12/2026

Vulnerability Publication Date: 2/12/2026

Reference Information

CVE: CVE-2026-70465

IAVA: 2026-A-0158

Detections

Analytics