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Fencer Intel
critical 9.8

CVE-2026-39808 kev in the critical feed json

A improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSandbox 4.4.0 t…

published 6mo ago modified 14d ago also EUVD-2026-22338

cvss
9.8
version 3.1, CNA
cisa kev
Exploited
added 2026-07-16
epss
93.2%
EPSS 93.2% chance of exploitation in 30 days, percentile 99.8%
public exploits
0
none known, plus a Nuclei check

Summary

A improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSandbox 4.4.0 through 4.4.8 may allow attacker to execute unauthorized code or commands via <insert attack vector here>

Patch / fix

cisa 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.

Is CVE-2026-39808 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Timeline

  1. CISA SSVC: exploitation active
  2. Published
  3. Added to CISA KEV
  4. CISA patch deadline

Known exploited

Added
3mo ago
Patch by
2026-07-19 (3mo ago)
Ransomware
Not known
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.
Vendor, product
Fortinet, FortiSandbox
CISA name
Fortinet FortiSandbox OS Command Injection Vulnerability

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
yes
Technical impact
total
Assessed
6mo ago

Exploit prediction

93.19% chance of exploitation in the next 30 days, higher than 99.8% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Nuclei template Fortinet FortiSandbox - Command Injection nuclei detection template
  • github.com https://github.com/samu-delucas/CVE-2026-39808 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Fortinet FortiSandbox
  • Fortinet FortiSandbox PaaS

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.