Known exploited vulnerability
CVE-2026-21643
The short answer
CVE-2026-21643 affects Fortinet FortiClientEMS and is rated critical (CVSS 9.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2026-04-13: attackers are using it, so patch it first.
What it is
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.
Weakness: CWE-89.
Severity
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploited (CISA KEV)
Yes, since Apr 13, 2026
Federal due date Apr 16, 2026
EPSS, next 30 days
98%
Higher than 100% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected products
FortiClientEMS. NVD's record lists the exact affected versions.
References
- fortiguard.fortinet.com/psirt/FG-IR-25-1142 Vendor Advisory
- github.com/0xBlackash/CVE-2026-21643/blob/main/cve-2026-21643.py Exploit
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21643 US Government Resource
Questions
Is CVE-2026-21643 being exploited?
Yes. CISA added CVE-2026-21643 to its Known Exploited Vulnerabilities catalog on 2026-04-13, with a federal remediation due date of 2026-04-16.
How do I fix CVE-2026-21643?
CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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