Zero-day vulnerability in FortiClientEMS

Missing authorization
CVE-2026-35616

Vulnerability details

Advisory: SB2026040404 - Authentication bypass and remote code execution in Fortinet FortiClientEMS

Vulnerable component: FortiClientEMS

CVE-ID: CVE-2026-35616

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-862 - Missing Authorization

Description:

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to missing authorization checks. A remote non-authenticated attacker can send a specially crafted HTTP request to certain API endpoint and execute arbitrary commands on the system.

Note, the vulnerability is being actively exploited in the wild. 

External links:

https://www.fortiguard.com/psirt/FG-IR-26-099

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.