Fortinet: Stack buffer overflow in WAD

Description

A Stack-based Buffer Overflow vulnerability [CWE-121] in FortiOS explicit proxy may allow an unauthenticated attacker who can bypass stack protection and ASLR to execute arbitrary code or commands in the context of the WAD daemon via crafted sockets, only if the explicit proxy is configured with Kerberos authentication and SOCKS enabled. Revised on 2026-08-12 00:00:00

What to do

Install the fixed versions listed in the official advisory. If you cannot update right away, apply the workarounds or mitigations it describes and limit access to the affected service.

Details

Vendor

Fortinet

Product

FortiOS

Affected versions

FortiOS 7.6: from 7.6.1 to 7.6.6 — fixed in 7.6.7 (from the advisory and NVD; check the exact builds in the official advisory)

CVSS score

5.6

Actively exploited

Not known at this time

Source

Fortinet PSIRT – original advisory

Published

August 12, 2026

The description and the recommended action are quoted from the public advisory (the action is our generic advice); severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.