Critical RCE-class vulnerability in a widely deployed Fortinet monitoring product; exploitation can lead to network compromise and credential exposure across enterprises.
CVE-2026-84390
FortiMonitorOnSight source-code secret disclosure enabling possible remote code execution
Is CVE-2026-84390 being exploited?
Not confirmed. CVE-2026-84390 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-84390?
CVE-2026-84390 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-84390?
Not known from our data. No patch reference has been recorded for CVE-2026-84390, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-84390 affect?
CVE-2026-84390 affects Fortinet FortiMonitorOnSight 7.2.0-7.2.2, Fortinet FortiMonitorOnSight 7.2.4-7.2.7. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-84390?
Follow vendor advisory, patch when available, rotate secrets, and restrict management access
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Embedded secrets/source code disclosure can let attackers bypass access controls, steal credentials, and achieve remote code execution or admin access.
Immediate action required
- affected>= 7.2.4 and <= 7.2.7
- affected>= 7.2.0 and <= 7.2.2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.