CVE-2026-21643
Exploited in the wild. In CISA KEV since 2026‑04‑13. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
An improper neutralization of special elements used in an sql command ('sql injection') vulnerability in Fortinet FortiClientEMS 7.4.4 may allow an unauthenticated attacker to execute unauthorized code or commands via specifically crafted HTTP requests.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Listed as exploited in the wild since 2026-04-13.
US federal agencies must remediate by 2026-04-16.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
94% chance of exploitation activity in the next 30 days, which ranks it in the 99th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
11 events over 139 days, from the signal feeds we watch.
- OpenVAS check added
- EPSS band changehigh → critical
- EPSS band changemoderate → high
- Patch availablerecord updated
- Added to CISA KEVepss band change
- Nuclei check added
Affected products
And 1 more affected product. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Scored 9.8 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
Sources
References in the record
- fortiguard.fortinet.com/psirt/FG-IR-25-1142
- github.com/0xBlackash/CVE-2026-21643/blob/main/cve-2026-21643.py
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21643
And 1 more reference. See all after sign-in
In the news
- Medusa ransomware gang has hit over 500 organizations, CISA warns
- CISA urges immediate action on actively exploited Fortinet flaws
- 3 Recently Patched Fortinet FortiSandbox Vulnerabilities in Hacker Crosshairs
- Critical Fortinet FortiSandbox flaws now exploited in attacks
- API Authentication Bypass in FortiClient EMS 7.4.5-7.4.6–CVE-2026-35616
- Pre-Authentication SQL Injection in FortiClient EMS 7.4.4 - CVE-2026-21643
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We'll flag the next CVE, public exploit or patch for FortiClientEMS, not every advisory. This one: actively exploited.
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