OS Command Injection through API endpoint
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
CVSSv3 Score: 9.1 An Improper Neutralization of Special Elements used in an OS Command ('OS command injection') vulnerability [CWE-78] in FortiSandbox may allow an unauthenticated attacker to execute unauthorized code or commands via crafted HTTP requests. Revised on 2026-04-14 00:00:00
CSIRTS triage
- What
- An unauthenticated attacker may execute unauthorized commands via crafted HTTP requests.
- Who is affected
- Users of FortiSandbox.
- Urgency
- Remediation is critical due to the high severity of potential exploitation.
- Action
- Apply security patches as soon as they are available.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://fortiguard.fortinet.com/psirt/FG-IR-26-100
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2026-39808Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 99.8% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-39808 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- criticalexploitedFortinet security advisory (AV26-351) – Update 2cccs
- highexploitedCISA Adds Three Known Exploited Vulnerabilities to Catalogcisa
- criticalexploitedCVE-2026-39808: Fortinet FortiSandbox OS Command Injection Vulnerabilitycisa-kev
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