Attackers Exploit Three Fortinet FortiSandbox Flaws, One Patched Last Week

Attackers Exploit Three Fortinet FortiSandbox Flaws, One Patched Last Week Ravie LakshmananJun 16, 2026Vulnerability / Threat Intelligence Bad actors are exploiting multiple security vulnerabilities in Fortinet FortiSandbox, according to threat intelligence firm Defused Cyber. In a post shared on X, the company said it has observed exploitation of CVE-2026-39813, CVE-2026-39808, and CVE-2026-25089 over the past 24 hours. CVE-2026-39813 (CVSS score: 9.1) refers to a path traversal vulnerability in FortiSandbox JRPC API that could allow an unauthenticated attacker to bypass authentication via specially crafted HTTP requests. The second flaw, CVE-2026-39808 (CVSS score: 9.1), is a case of operating system command injection that could allow an unauthenticated attacker to execute unauthorized code or commands via crafted HTTP requests. Both vulnerabilities were patched by Fortinet in April 2026. CVE-2026-25089 (CVSS score: 9.1), on the other hand, was fixed last week, with Fortinet describing it as an operating system command injection impacting FortiSandbox, FortiSandbox Cloud, and FortiSandbox PaaS WEB UI that could allow an unauthenticated attacker to execute unauthorized commands via specifically crafted HTTP requests. Defused Cyber noted that the exploit for CVE-2026-25089 not only shows signs of being developed using an artificial intelligence (AI) model, but is also faulty. A working exploit for the vulnerability has not been publicly disclosed. Vulnerabilities in Fortinet appliances have become a lightning rod for attackers in recent years. In April 2026, Fortinet released out-of-band patches for a critical security flaw impacting FortiClient EMS (CVE-2026-35616, CVSS score: 9.1) that it said has been exploited in the wild. Found this article interesting? Follow us on Google News, Twitter and LinkedIn to read more exclusive content we post. SHARE     Tweet Share Share SHARE  AI, Command Injection, cybersecurity, Fortinet, Path Traversal, Threat Intelligence, Vulnerability ⚡ Top Stories This Week Researchers Build Self-Replicating AI Worm That Operates Entirely on Local, Open-Weight Models Critical Splunk Enterprise Flaw Lets Attackers Run Code Without Authentication ThreatsDay Bulletin: Worm Code Leaked, AI Agent Phished, Claude Code Patch + 28 New Stories New GreatXML Exploit Bypasses Windows BitLocker via Recovery Partition XML Files Microsoft Defender RoguePlanet Zero-Day Grants SYSTEM Access on Updated Windows China-Linked Hackers Backdoored Linux Login Software to Hide for Nearly a Decade Over 400 Arch Linux AUR Packages Hijacked to Deploy Infostealer and eBPF Rootkit Ivanti, Fortinet, and SAP Release Patches for Multiple Critical Vulnerabilities U.S. Orders Anthropic to Suspend Fable 5 and Mythos 5 Access for Foreign Nationals Anthropic Releases Claude Fable 5, Its Most Powerful AI Yet, With Cyber Safeguards Microsoft Patches Record 206 Flaws, Including Three Zero-Days and Critical RCE Bugs Chrome V8 Zero-Day CVE-2026-11645 Exploited in the Wild - Patch Now Cybersecurity Stars Awards 2026: Winners Announced Across 95 Categories Agentjacking Attack Tricks AI Coding Agents Into Running Malicious Code ⭐ Featured Resources Have You Outgrown Your MDR? 7 Warning Signs Every CISO Should Check Get the 2026 Guide to Govern and Secure Enterprise AI Agents at Scale AI Can’t Stop Every Attack. Learn How Zero Trust Can Block What’s Unknown [Watch Demo] See Which Security Gaps Attackers Could Exploit First