CVE-2025-62439: Firewall policy bypass in FSSO Terminal Services Agent

Published Feb 10, 2026
·
Updated

An Improper Verification of Source of a Communication Channel vulnerability [CWE-940] in FortiOS FSSO Terminal Services Agent may allow an authenticated user with knowledge of FSSO policy configurations to gain unauthorized access to protected network resources via crafted requests.

Other sources

An Improper Verification of Source of a Communication Channel vulnerability [CWE-940] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions may allow an authenticated user with knowledge of FSSO policy configurations to gain unauthorized access to protected network resources via crafted requests.

MITRE

Affected Software

4 affected componentsFixes available
Fortinet FortiOS>=7.6.0<=7.6.4
Fortinet FortiOS>=7.4.0<=7.4.9
Fortinet FortiOS>=7.2
Fortinet FortiOS>=7.0

Remediation

Information

Upgrade to upcoming FortiOS version 8.0.0 or above Upgrade to FortiOS version 7.6.5 or above Upgrade to FortiOS version 7.4.10 or above

Event History

Feb 10, 2026
Advisory Published
via FortiGuard·12:00 AM
Data Sourced
via FortiGuard·12:00 AM
DescriptionSeverityWeaknessAffected Software
CVE Published
via MITRE·03:39 PM
Data Sourced
via MITRE·03:39 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·04:16 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2025-62439?

CVE-2025-62439 is classified as a high severity vulnerability due to its potential to allow unauthorized access to protected resources.

2

How do I fix CVE-2025-62439?

To mitigate CVE-2025-62439, update FortiOS to version 7.6.5 or later, or apply the appropriate patches if available for affected versions.

3

Who is affected by CVE-2025-62439?

Organizations using FortiOS versions 7.6.0 to 7.6.4, 7.4.0 to 7.4.9, and certain 7.2 and 7.0 versions are at risk from CVE-2025-62439.

4

What type of vulnerability is CVE-2025-62439?

CVE-2025-62439 is categorized as an Improper Verification of Source of a Communication Channel vulnerability, which can lead to policy bypass.

5

Can authenticated users exploit CVE-2025-62439?

Yes, authenticated users knowledgeable about the FSSO policy configurations can exploit CVE-2025-62439 to gain unauthorized access.

Contact

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