CVE-2025-62439

Firewall policy bypass via unverified FSSO requests

Published Feb 10, 2026 · Updated Feb 10, 2026

Source-verification failure in Fortinet FortiOS allows local users to bypass FSSO firewall policies via crafted requests. The FSSO Terminal Services Agent accepts crafted requests without properly verifying that they originate from the expected communication peer. Affected releases are 7.0.0 through 7.0.19, 7.2.0 through 7.2.13, 7.4.0 through 7.4.9, and 7.6.0 through 7.6.4; exploitation requires authentication and knowledge of FSSO policy configurations, and grants unauthorized access to protected network resources.

CVSS severity4.2
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Source-verification failure in Fortinet FortiOS allows local users to bypass FSSO firewall policies via crafted requests. The FSSO Terminal Services Agent accepts crafted requests without properly verifying that they originate from the expected communication peer. Affected releases are 7.0.0 through 7.0.19, 7.2.0 through 7.2.13, 7.4.0 through 7.4.9, and 7.6.0 through 7.6.4; exploitation requires authentication and knowledge of FSSO policy configurations, and grants unauthorized access to protected network resources.

The record

CVE
CVE-2025-62439
Published
Feb 10, 2026
Updated
Feb 10, 2026
Vendor
Fortinet
Product
FortiOS
Classifications
CWE-940, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.0.0 <=7.0.19
  2. Affected versionversion=7.2.0 <=7.2.13
  3. Affected versionversion=7.4.0 <=7.4.9
  4. Affected versionversion=7.6.0 <=7.6.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Fortinet · FortiOSversion=7.0.0 <=7.0.19; version=7.2.0 <=7.2.13; version=7.4.0 <=7.4.9; version=7.6.0 <=7.6.4

Published CVSS scores

4.2Fortinet, Inc.CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-940Improper Verification of Source of a Communication Channel
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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