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Fortinet
Confidence HighMar 30, 2026fortinet.com

Critical FortiClient EMS Flaws Actively Exploited to Deploy Credential Stealers

PatternExternal actor · Malware · Confidentiality impact

Threat actors are actively exploiting critical vulnerabilities in Fortinet FortiClient Endpoint Management Server (EMS), including CVE-2026-35616 and CVE-2026-21643. CVE-2026-35616, a critical security flaw, was actively exploited in the wild to deploy credential-stealing malware (EKZ Infostealer), prompting an emergency patch in April 2026. CVE-2026-21643 is also mentioned in active exploitation campaigns.

Signal date
Mar 30, 2026
Updated
Jun 19, 2026
Confidence
High
Sources
2 sources

Signal context

First seen: Mar 30, 2026

Last updated: Jun 19, 2026

Status: Public signal

Key points

  • CVE-2026-35616 (CVSS 9.1): Critical security flaw in FortiClient EMS actively exploited.
  • Exploitation used to deploy EKZ Infostealer malware.
  • Emergency patch released in April 2026.

Signal analysis

Beta

It helps compare this signal with other published signals without treating the labels as final determinations.

Affected organization
Fortinet logo
Fortinet

Likely country: Location not provided

Threat source
Malware activity

Watch ransomware, endpoint compromise and business interruption exposure.

  • Source type: outside the affected organization
Business impact
Potential extortion or operational risk

Impact area: Confidentiality

Likely asset: User or customer data, Server or cloud data store

Trend context
23 signals with similar action pattern
  • 1 signal in the same sector
  • 90 signals with the same likely impact area
  • 1 signal linked to this organization/domain
Mentioned entities
FortinetData DisclosureCritical FortiClient EMS Flaws ActivelyExploitedDeploy Credential Stealers ThreatFortinet FortiClient Endpoint Management ServerEMSCVE-2026-35616 and CVE-2026-21643. CVE-2026-35616EKZ InfostealerCVE-2026-21643

External sources

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