Exploited CVEs / Fortinet / CVE-2026-39808
CVE-2026-39808
Fortinet FortiSandbox OS Command Injection Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2026-07-19 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Fortinet PSIRT Advisories, linked below.
Actively exploited Fortinet FortiSandbox vulnerability, Critical severity, CVSS 9.8. Added to the CISA KEV catalog 2026-07-16.
Risk summary
Updated July 26, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Senserva AI Opinion for CVE-2026-39808
This is an unauthenticated OS command injection in Fortinet FortiSandbox, reachable through crafted HTTP requests with no credentials needed, and it carries a Severity of Critical (CVSS 9.8) with a 90 percent EPSS exploit probability. CISA confirmed active exploitation and added it to the KEV catalog on 2026-07-16, so any FortiSandbox with an exposed management or web interface is a live target. Because FortiSandbox inspects suspected malware, a compromise hands attackers control of a device that already sees your threat traffic.
Do this: Identify all FortiSandbox appliances, apply Fortinet's fixed release now, and remove any HTTP/management interface exposure from untrusted networks until patched.
AI-generated from public data, 2026-07-25. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-39808
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2026-39808
Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.
CISA required action
Federal (BOD 22-01) remediation due date: 2026-07-19 (past due).
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Official fix for CVE-2026-39808
The authoritative fix and affected-version list are published by the vendor. Find the FortiSandbox advisory on Fortinet PSIRT Advisories.
Common questions about CVE-2026-39808
Is CVE-2026-39808 actively exploited?
Yes. CVE-2026-39808 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2026-07-16, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 90%.
What is the CISA deadline and required action for CVE-2026-39808?
CISA set the federal (BOD 22-01) remediation due date at 2026-07-19, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
What fixes CVE-2026-39808?
The authoritative fix is in the vendor advisory: see Fortinet PSIRT Advisories for the patched FortiSandbox versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.
Can I ask my own AI about CVE-2026-39808?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-39808's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).
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Authoritative references
Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.
