Origin Validation Error in Fortinet's FortiClient for Mac and Windows
CVE-2026-121529

9.1CRITICAL

Key Information:

Vendor

Fortinet
Status
Forticlientmac
Forticlientwindows
Forticlientwindowspam
Vendor
CVE Published:
10 November 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-121529?

An origin validation error has been identified in Fortinet's FortiClient products for both Mac and Windows platforms. This vulnerability potentially allows an unauthorized remote attacker to execute code or commands without proper authorization. Successful exploitation of this vulnerability necessitates some level of interaction with the victim, underscoring the importance of user awareness and system security. Affected versions include FortiClientMac 7.4.0 to 7.4.7, FortiClientWindows 7.4.0 to 7.4.7, and others. For detailed technical information, refer to the Fortinet advisory.

Affected Version(s)

FortiClientMac 7.4.0 <= 7.4.7

FortiClientWindows 7.4.0 <= 7.4.7

FortiClientWindows 7.2.0 <= 7.2.14

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

cve-2026-121529-forticlient-cors-rce
Created by Ghost-Bx1

Fortinet2Shell
Created by googlesky

CVE-2026-121529
Created by googlesky

References

https://fortiguard.fortinet.com/psirt/FG-IR-26-194

CVSS V3.1

Score:
9.1
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

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