【Vulnerability Alert】FortiMonitorOnSight Contains a Critical Security Vulnerability (CVE-2026-84390)

• Subject:【Vulnerability Alert】FortiMonitorOnSight Contains a Critical Security Vulnerability (CVE-2026-84390)

• Description:
  • Forwarded from TWCERT/CC Security Advisory TWCERTCC-200-202609-00000014
  • The FortiMonitorOnSight Web portal has a sensitive information exposure in source code vulnerability (CVE-2026-84390, CVSS: 9.6). This vulnerability may allow unauthenticated remote attackers to bypass authentication by spoofing or reusing JWTs.
• Affected Platforms:
  • FortiMonitorOnSight versions 7.2.0 through 7.2.2
  • FortiMonitorOnSight versions 7.2.4 through 7.2.7
• Recommended Actions:
  • Please update to the following version: FortiMonitorOnSight 7.2.8 and later
• References:
  1. https://www.twcert.org.tw/tw/cp-169-11196-1a15a-1.html

Computer and Communication Center
Network System Division