CVE-2026-21643 — Forticlientems
CRITICALCVE-2026-21643 is a critical-severity (CVSS 9.8) SQL Injection vulnerability in fortinet forticlientems. It is in CISA's Known Exploited Vulnerabilities catalog (added 2026-04-13) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
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…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2026-04-13. Federal agencies were required to remediate by 2026-04-16.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2026-21643.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-21643 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 394,415 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
Description
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.
Affected Products
forticlientemsfortinetResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every fortinet forticlientems deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2026-21643 yet — track the fortinet forticlientems advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Until you can upgrade, make sure every query built from user input uses parameterised statements or a prepared-statement API rather than string concatenation, and reduce the database account's privileges so an injected query cannot read or alter data beyond what the feature needs. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
How to detect CVE-2026-21643
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2026-21643 -u https://target- Template
- Fortinet FortiClientEMS 7.4.4 - SQL Injection
- Severity
- critical
- Impact
- An unauthenticated remote attacker can execute arbitrary SQL queries against the backend PostgreSQL database, potentially extracting sensitive data, modifying database contents, or achieving remote code execution through PostgreSQL-specific functions (e.g., COPY, lo_import, pg_read_file).
- Remediation
- Upgrade FortiClientEMS to a patched version as recommended by Fortinet. As a workaround, restrict network access to the FortiClientEMS management interface and apply WAF rules to filter malicious Site header values.
Template by ProjectDiscovery nuclei-templates (ritikchaddha), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2026-21643 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.