Stack-based buffer overflow in FortiOS - CVE-2026-126258
Published: November 11, 2026
Vulnerability identifier: #VU165160
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-126258
CWE-ID: CWE-121
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to stack-based buffer overflow in wad. An unauthenticated attacker with wad port access can crash proxy or ZTNA sessions via crafted HTTP or HTTPS requests.
Affected software
FortiOS
How to mitigate CVE-2026-126258
Install update from vendor's website.
FortiOS - addressed in versions 7.6.8, 8.0.1