Cyber Resilience

CVE-2026-25089

RCE in Fortinet Fortisandbox 4.2.0 – 4.2.8

CISA KEVActive ExploitationRCECommand Injection
Published
09 June 2026
Modified
17 July 2026
KEV Added
16 July 2026
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.74 99.4th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2026-25089 is a critical-severity OS Command Injection (CWE-78) vulnerability in Fortinet Fortisandbox. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 0.6% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-25089 is an OS command injection vulnerability, tracked under CWE-78, that affects multiple versions of Fortinet FortiSandbox including 5.0.0-5.0.5, 4.4.0-4.4.8, all releases of 4.2, and corresponding FortiSandbox Cloud and PaaS builds 5.0.4-5.0.5. The flaw stems from improper neutralization of special elements in OS commands and carries a CVSS 3.1 base score of 9.8.

An unauthenticated remote attacker can exploit the issue by sending specially crafted HTTP requests to the affected appliance, resulting in arbitrary command execution with full control over confidentiality, integrity, and availability of the system.

The Fortinet advisory FG-IR-26-141 provides official details on the vulnerability and is the primary source for mitigation guidance, including recommended upgrade paths for each affected branch.

EPSS remains low and unchanged at 0.0203 with no observed increase after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSandbox 5.0.0 through 5.0.5, FortiSandbox 4.4.0 through 4.4.8, FortiSandbox 4.2 all versions, FortiSandbox Cloud 5.0.4 through 5.0.5, FortiSandbox PaaS 5.0.4 through 5.0.5 may…

more

allow an unauthenticated attacker to execute unauthorized commands via specifically crafted HTTP requests

CWE(s)
KEV Date Added
16 July 2026

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-39808Same product: Fortinet Fortisandboxboth on KEV
CVE-2025-53679Same product: Fortinet Fortisandbox
CVE-2025-58034Same vendor: Fortinetboth on KEV
CVE-2025-53949Same product: Fortinet Fortisandbox
CVE-2026-25836Same product: Fortinet Fortisandbox Cloud
CVE-2024-21755Same product: Fortinet Fortisandbox
CVE-2023-47540Same product: Fortinet Fortisandbox
CVE-2024-21756Same product: Fortinet Fortisandbox
CVE-2024-27778Same product: Fortinet Fortisandbox
CVE-2024-52961Same product: Fortinet Fortisandbox

Affected Assets

fortinet
fortisandbox
4.2.0 — 4.2.8 · 4.4.0 — 4.4.9 · 5.0.0 — 5.0.6
fortinet
fortisandbox cloud
5.0.4 — 5.0.6
fortinet
fortisandbox paas
5.0.4 — 5.0.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover missing or incorrect command sanitization during development.

Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.

Least privilege reduces the permissions available to any process that could be subverted by injected commands.

Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.

Secure engineering principles require proper neutralization of untrusted input before command construction.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References