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Fortinet Releases Security Updates for FortiOS and FortiSwitch Manager

Advisory addresses a vulnerability which if exploited could allow a remote unauthenticated attacker to perform arbitrary code or command execution

Threat ID:
CC-4736
Threat Severity:
Medium
Published:
14 January 2026 1:34 PM
Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

Advisory addresses a vulnerability which if exploited could allow a remote unauthenticated attacker to perform arbitrary code or command execution

Threat details

Exploitation of CVE-2025-25249

Security researchers have reported active exploitation of CVE-2025-25249 in the wild to deploy PivotC2 malware. The National Vulnerability Database has reclassified the CVSS score of this vulnerability to 9.8.

Introduction

Fortinet has released security updates to address a high severity vulnerability in FortiOS and FortiSwitch Manager. Successful exploitation by a remote unauthenticated attacker could allow for arbitrary code or command execution.

  • CVE-2025-25249 - Heap-Based Buffer Overflow vulnerability - CVSSv3 score: 9.8

Threat updates

Date Update
9 Sep 2026 CVE-2025-25249 CVSS Score Reclassified from 7.4 to 9.8

The following has been updated to reflect this change:

  • Introduction
  • Exploitation of CVE-2025-25249

Remediation advice

Affected organisations are encouraged to review the Fortinet PSIRT FG-IR-25-084 and apply the relevant updates as soon as possible.

Definitive source of threat updates

Last edited: 9 September 2026 12:09 pm