Fortinet warns of 5-year-old FortiOS 2FA bypass still exploited in attacks

BleepingComputer

December 29, 2025 at 11:16 AM

Actively Exploited

Overview

Fortinet has issued a warning about a vulnerability in FortiOS that has been around for five years but is still being exploited by attackers. This flaw allows unauthorized users to bypass two-factor authentication (2FA) on FortiGate firewalls, which are widely used by organizations to secure their networks. The continued exploitation of this vulnerability poses a significant risk to companies relying on these firewalls, as it can lead to unauthorized access and potential data breaches. Users of FortiGate firewalls are urged to take immediate action to protect their systems by applying available security updates. This situation serves as a reminder of the importance of keeping software up to date and addressing known vulnerabilities promptly.

Key Takeaways

Active Exploitation: This vulnerability is being actively exploited by attackers. Immediate action is recommended.
Affected Systems: FortiGate firewalls running FortiOS
Action Required: Users should apply the latest security patches from Fortinet to mitigate this vulnerability.
Timeline: Ongoing since 2018

Original Article Summary

Fortinet has warned customers that threat actors are still actively exploiting a critical FortiOS vulnerability that allows them to bypass two-factor authentication (2FA) when targeting vulnerable FortiGate firewalls. [...]

Impact

FortiGate firewalls running FortiOS

Exploitation Status

This vulnerability is confirmed to be actively exploited by attackers in real-world attacks. Organizations should prioritize patching or implementing workarounds immediately.

Timeline

Ongoing since 2018

Remediation

Users should apply the latest security patches from Fortinet to mitigate this vulnerability.

Additional Information

This threat intelligence is aggregated from trusted cybersecurity sources. For the most up-to-date information, technical details, and official vendor guidance, please refer to the original article linked below.

Related Topics: This incident relates to Fortinet, Vulnerability, Critical.

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