CVE-2026-39813 — AI Deep Analysis Summary

Q: Root Cause? (CWE/Flaw)

🛡️ **Root Cause**: **CWE-24** (Path Traversal). 🔍 **Flaw**: Improper restriction of **relative path names** allows access to restricted directories outside the intended scope.

Q: Who is affected? (Versions/Components)

📦 **Affected Versions**: • **5.0.0** to **5.0.5** • **4.4.0** to **4.4.8** 🏢 **Vendor**: Fortinet (FortiSandbox APT protection device).

Q: What can hackers do? (Privileges/Data)

💀 **Attacker Capabilities**: • **Privilege Escalation**: Gain higher system access. • **Data Access**: Read/Modify critical files. • **Impact**: Complete control over the sandbox environment.

Q: Is there a public Exp? (PoC/Wild Exploitation)

📜 **Public Exploit**: **None detected** in current data. ⚠️ **Status**: CVSS Score is **9.8 (Critical)**, so wild exploitation is highly likely soon despite no public PoC yet.

Q: How to self-check? (Features/Scanning)

🔎 **Self-Check**: 1. Verify FortiSandbox version (4.4.x or 5.0.x). 2. Check for **Path Traversal** signatures in WAF/IPS logs. 3. Scan for unauthorized file access attempts.

Q: Is it fixed officially? (Patch/Mitigation)

🩹 **Official Fix**: **Yes**. 📢 **Reference**: Fortinet PSIRT **FG-IR-26-112**. ✅ **Action**: Update to the latest patched version immediately.

Q: What if no patch? (Workaround)

🚧 **No Patch Workaround**: • **Isolate**: Restrict network access to the device. • **Monitor**: Enable strict logging for file system operations. • **Restrict**: Limit API access if possible.

Q: Is it urgent? (Priority Suggestion)

🔥 **Urgency**: **CRITICAL (P0)**. 🚀 **Priority**: **Immediate Patching Required**. • CVSS 9.8 + No Auth + Remote = **High Risk**. Do not delay.

Updated May 06, 2026 CVSS 9.1 · Critical

This is a summary of the AI-generated 10-question deep analysis. The full version (longer answers, follow-up Q&A, related CVEs) requires login. Read the full analysis →

Q1What is this vulnerability? (Essence + Consequences)

🚨 **Essence**: A critical **Path Traversal** flaw in FortiSandbox.…

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Q2Root Cause? (CWE/Flaw)

🛡️ **Root Cause**: **CWE-24** (Path Traversal). <br>🔍 **Flaw**: Improper restriction of **relative path names** allows access to restricted directories outside the intended scope.

Q3Who is affected? (Versions/Components)

📦 **Affected Versions**: <br>• **5.0.0** to **5.0.5** <br>• **4.4.0** to **4.4.8** <br>🏢 **Vendor**: Fortinet (FortiSandbox APT protection device).

Q4What can hackers do? (Privileges/Data)

💀 **Attacker Capabilities**: <br>• **Privilege Escalation**: Gain higher system access. <br>• **Data Access**: Read/Modify critical files. <br>• **Impact**: Complete control over the sandbox environment.

Q5Is exploitation threshold high? (Auth/Config)

🔓 **Exploitation Threshold**: **LOW**. <br>• **Network**: Remotely exploitable (AV:N). <br>• **Complexity**: Low (AC:L). <br>• **Auth**: **No authentication required** (PR:N).…

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Q6Is there a public Exp? (PoC/Wild Exploitation)

📜 **Public Exploit**: **None detected** in current data. <br>⚠️ **Status**: CVSS Score is **9.8 (Critical)**, so wild exploitation is highly likely soon despite no public PoC yet.

Q7How to self-check? (Features/Scanning)

🔎 **Self-Check**: <br>1. Verify FortiSandbox version (4.4.x or 5.0.x). <br>2. Check for **Path Traversal** signatures in WAF/IPS logs. <br>3. Scan for unauthorized file access attempts.

Q8Is it fixed officially? (Patch/Mitigation)

🩹 **Official Fix**: **Yes**. <br>📢 **Reference**: Fortinet PSIRT **FG-IR-26-112**. <br>✅ **Action**: Update to the latest patched version immediately.

Q9What if no patch? (Workaround)

🚧 **No Patch Workaround**: <br>• **Isolate**: Restrict network access to the device. <br>• **Monitor**: Enable strict logging for file system operations. <br>• **Restrict**: Limit API access if possible.

Q10Is it urgent? (Priority Suggestion)

🔥 **Urgency**: **CRITICAL (P0)**. <br>🚀 **Priority**: **Immediate Patching Required**. <br>• CVSS 9.8 + No Auth + Remote = **High Risk**. Do not delay.

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Vulnerability detail Full AI analysis (login) Fortinet CWE-24