Multiple Vulnerabilities in Fortinet Products Could Allow for Arbitrary Code Execution

MS-ISAC ADVISORY NUMBER:

2026-003

DATE(S) ISSUED:

01/13/2026

OVERVIEW:

Multiple vulnerabilities have been discovered in Fortinet products, the most severe of which could allow for arbitrary code execution.

  • FortiSandbox is an advanced threat detection solution from Fortinet that uses sandboxing to analyze suspicious files and network traffic for advanced threats like zero-day malware and ransomware.
  • FortiWeb is a web application firewall (WAF) that protects web applications and APIs from cyberattacks like SQL injection and cross-site scripting, while also helping to meet compliance requirements.
  • FortiVoice is a unified communications solution that combines voice, chat, conferencing, and fax into a single, secure platform for businesses and schools.
  • FortiOS is the Fortinet’s proprietary Operation System which is utilized across multiple product lines.
  • FortiProxy is a secure web gateway product from Fortinet that protects users from internet-borne attacks, enforces compliance, and improves network performance.
  • FortiClientEMS is a centralized management platform for deploying, configuring, monitoring, and enforcing security policies across numerous endpoints (computers) running the FortiClient agent.
  • FortiSwitchManager is Fortinet's dedicated, on-premise platform for centrally managing FortiSwitch devices in large deployments.
  • FortiFone is Fortinet's secure, enterprise-grade unified communications solution.

Successful exploitation of the most severe of these vulnerabilities could allow for arbitrary code execution in the context of the affected service account. Depending on the privileges associated with the service account an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Service accounts that are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

THREAT INTELLIGENCE:

There are currently no reports of these vulnerabilities being exploited in the wild.

SYSTEMS AFFECTED:

  • FortiVoice 7.2.0 through 7.2.2
  • FortiVoice 7.0.0 through 7.0.7
  • FortiClientEMS 7.4.3 through 7.4.4
  • FortiClientEMS 7.4.0 through 7.4.1
  • FortiClientEMS 7.2.0 through 7.2.10
  • FortiClientEMS 7.0 all versions
  • FortiOS 7.6.0 through 7.6.3
  • FortiOS 7.4.0 through 7.4.8
  • FortiOS 7.2.0 through 7.2.11
  • FortiOS 7.0.0 through 7.0.17
  • FortiOS 6.4.0 through 6.4.16
  • FortiSASE 25.2.b
  • FortiSASE 25.1.a.2
  • FortiSwitchManager 7.2.0 through 7.2.6
  • FortiSwitchManager 7.0.0 through 7.0.5
  • FortiSandbox 5.0.0 through 5.0.4
  • FortiSandbox 4.4 all versions
  • FortiSandbox 4.2 all versions
  • FortiSandbox 4.0 all versions
  • FortiFone 7.0.0 through 7.0.1
  • FortiFone 3.0.13 through 3.0.23
  • FortiSIEM 7.4.0
  • FortiSIEM 7.3.0 through 7.3.4
  • FortiSIEM 7.2.0 through 7.2.6
  • FortiSIEM 7.1.0 through 7.1.8
  • FortiSIEM 7.0.0 through 7.0.4
  • FortiSIEM 7.0.0 through 7.0.4

RISK:

Government:
Large and medium government entitiesHIGH
Small governmentMEDIUM
Businesses:
Large and medium business entitiesHIGH
Small business entitiesMEDIUM
Home Users:
LOW

TECHNICAL SUMMARY:

Multiple vulnerabilities have been discovered in Fortinet products, the most severe of which could allow for arbitrary code execution. Details of the vulnerabilities are as follows: 

Tactic: Initial Access (TA0001)

Technique: Exploitation Public-Facing Application (T1190):

  • A heap-based buffer overflow vulnerability [CWE-122] in FortiOS and FortiSwitchManager cw_acd daemon may allow a remote unauthenticated attacker to execute arbitrary code or commands via specifically crafted requests. (CVE-2025-25249)
  • An improper neutralization of special elements used in an OS command ('OS Command Injection') vulnerability [CWE-78] in FortiSIEM may allow an unauthenticated attacker to execute unauthorized code or commands via crafted TCP requests. (CVE-2025-64155)

Details of lower severity vulnerabilities:

  • An improper limitation of a pathname to a restricted directory ('path traversal') vulnerability in FortiVoice may allow a privileged attacker to delete files from the underlying filesystem via crafted HTTP or HTTPs requests. (CVE-2025-58693)
  • An improper neutralization of special elements used in an SQL command ('SQL Injection') vulnerability [CWE-89] in FortiClientEMS may allow an authenticated attacker with at least read-only admin permission to execute unauthorized SQL code or commands via crafted HTTP or HTTPs requests. (CVE-2025-59922)
  • A Server-Side Request Forgery (SSRF) vulnerability [CWE-918] in FortiSandbox may allow an authenticated attacker to proxy internal requests limited to plaintext endpoints only via crafted HTTP requests. (CVE-2025-67685)
  • An exposure of sensitive information to an unauthorized actor [CWE-200] vulnerability in FortiFone Web Portal page may allow an unauthenticated attacker to obtain the device configuration via crafted HTTP or HTTPS requests. (CVE-2025-47855)

Successful exploitation of the most severe of these vulnerabilities could allow for arbitrary code execution in the context of the affected service account. Depending on the privileges associated with the service account an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Service accounts that are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

RECOMMENDATIONS:

We recommend the following actions be taken:

  • Apply the stable channel update provided by Fortinet to vulnerable systems immediately after appropriate testing. (M1051: Update Software)
  • Safeguard 7.1 : Establish and Maintain a Vulnerability Management Process: Establish and maintain a documented vulnerability management process for enterprise assets. Review and update documentation annually, or when significant enterprise changes occur that could impact this Safeguard.
  • Safeguard 7.2 : Establish and Maintain a Remediation Process: Establish and maintain a risk-based remediation strategy documented in a remediation process, with monthly, or more frequent, reviews.
  • Safeguard 7.4: Perform Automated Application Patch Management: Perform application updates on enterprise assets through automated patch management on a monthly, or more frequent, basis.
  • Safeguard 7.6 : Perform Automated Vulnerability Scans of Externally-Exposed Enterprise Assets: Perform automated vulnerability scans of externally-exposed enterprise assets using a SCAP-compliant vulnerability scanning tool. Perform scans on a monthly, or more frequent, basis.
  • Safeguard 7.7 : Remediate Detected Vulnerabilities: Remediate detected vulnerabilities in software through processes and tooling on a monthly, or more frequent, basis, based on the remediation process.
  • Safeguard 16.13 Conduct Application Penetration Testing: Conduct application penetration testing. For critical applications, authenticated penetration testing is better suited to finding business logic vulnerabilities than code scanning and automated security testing. Penetration testing relies on the skill of the tester to manually manipulate an application as an authenticated and unauthenticated user.
  • Safeguard 12.1: Ensure Network Infrastructure is Up-to-Date: Ensure network infrastructure is kept up-to-date. Example implementations include running the latest stable release of software and/or using currently supported network-as-a-service (NaaS) offerings. Review software versions monthly, or more frequently, to verify software support.
  • Safeguard 18.1 : Establish and Maintain a Penetration Testing Program: Establish and maintain a penetration testing program appropriate to the size, complexity, and maturity of the enterprise. Penetration testing program characteristics include scope, such as network, web application, Application Programming Interface (API), hosted services, and physical premise controls; frequency; limitations, such as acceptable hours, and excluded attack types; point of contact information; remediation, such as how findings will be routed internally; and retrospective requirements.
  • Safeguard 18.2 : Perform Periodic External Penetration Tests: Perform periodic external penetration tests based on program requirements, no less than annually. External penetration testing must include enterprise and environmental reconnaissance to detect exploitable information. Penetration testing requires specialized skills and experience and must be conducted through a qualified party. The testing may be clear box or opaque box.
  • Safeguard 18.3 : Remediate Penetration Test Findings: Remediate penetration test findings based on the enterprise’s policy for remediation scope and prioritization.
  • Apply the Principle of Least Privilege to all systems and services. Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack. (M1026: Privileged Account Management)
  • Safeguard 4.7: Manage Default Accounts on Enterprise Assets and Software: Manage default accounts on enterprise assets and software, such as root, administrator, and other pre-configured vendor accounts. Example implementations can include: disabling default accounts or making them unusable.
  • Safeguard 5.4: Restrict Administrator Privileges to Dedicated Administrator Accounts: Restrict administrator privileges to dedicated administrator accounts on enterprise assets. Conduct general computing activities, such as internet browsing, email, and productivity suite use, from the user’s primary, non-privileged account.
  • Vulnerability scanning is used to find potentially exploitable software vulnerabilities to remediate them. (M1016: Vulnerability Scanning)
  • Safeguard 16.13: Conduct Application Penetration Testing: Conduct application penetration testing. For critical applications, authenticated penetration testing is better suited to finding business logic vulnerabilities than code scanning and automated security testing. Penetration testing relies on the skill of the tester to manually manipulate an application as an authenticated and unauthenticated user.
  • Use capabilities to detect and block conditions that may lead to or be indicative of a software exploit occurring. (M1050: Exploit Protection)
  • Safeguard 10.5: Enable Anti-Exploitation Features: Enable anti-exploitation features on enterprise assets and software, where possible, such as Microsoft® Data Execution Prevention (DEP), Windows® Defender Exploit Guard (WDEG), or Apple® System Integrity Protection (SIP) and Gatekeeper™.
  • Architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services that should not be exposed from the internal network. Configure separate virtual private cloud (VPC) instances to isolate critical cloud systems. (M1030: Network Segmentation)
  • Safeguard 12.2: Establish and Maintain a Secure Network Architecture: Establish and maintain a secure network architecture. A secure network architecture must address segmentation, least privilege, and availability, at a minimum.
  • Use capabilities to detect and block conditions that may lead to or be indicative of a software exploit occurring. (M1050: Exploit Protection)
  • Safeguard 10.5: Enable Anti-Exploitation Features: Enable anti-exploitation features on enterprise assets and software, where possible, such as Microsoft® Data Execution Prevention (DEP), Windows® Defender Exploit Guard (WDEG), or Apple® System Integrity Protection (SIP) and Gatekeeper™.


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