CVE-2026-21743: High severity Fortinet FortiAuthenticator vulnerability

Published Feb 10, 2026
·
Updated

A missing authorization vulnerability in Fortinet FortiAuthenticator 6.6.0 through 6.6.6, FortiAuthenticator 6.5 all versions, FortiAuthenticator 6.4 all versions, FortiAuthenticator 6.3 all versions may allow a read-only user to make modification to local users via a file upload to an unprotected endpoint.

Affected Software

2 affected components
Fortinet FortiAuthenticator>=6.6.0<=6.6.6, =6.5, =6.4, =6.3
Fortinet FortiAuthenticator>=6.3.0<6.6.7

Remediation

Information

Upgrade to FortiAuthenticator version 8.0.0 or above Upgrade to FortiAuthenticator version 6.6.7 or above

Event History

Feb 10, 2026
CVE Published
via MITRE·03:39 PM
Data Sourced
via MITRE·03:39 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·04:16 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-21743?

CVE-2026-21743 has been classified with a medium severity due to the potential for unauthorized modifications by low-privileged users.

2

How do I fix CVE-2026-21743?

To fix CVE-2026-21743, upgrade Fortinet FortiAuthenticator to version 6.6.7 or later, or to version 6.5.1 or later.

3

Who is affected by CVE-2026-21743?

CVE-2026-21743 affects users of Fortinet FortiAuthenticator versions 6.3 through 6.6.6 and all versions of 6.5 and 6.4.

4

What type of vulnerability is CVE-2026-21743?

CVE-2026-21743 is categorized as a missing authorization vulnerability, which allows unintended modifications by unauthorized users.

5

Can CVE-2026-21743 lead to data breaches?

Yes, CVE-2026-21743 could potentially lead to data breaches if an attacker exploits the vulnerability to modify user accounts or access sensitive information.

Contact

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