CVE-2026-21643: Fortinet FortiClient EMS SQL Injection Vulnerability

Patch now

CRITICAL 9.8EXPLOITEDREMOTEDOWNGRADE

CVE-2026-21643 is a critical-severity flaw (CVSS 9.8) affecting forticlientems, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	97.7% (top 1%)
CISA exploited list	Yes, fix due 2026-04-16
Weakness	CWE-89
Published	2026-02-06
Last modified	2026-06-17

Publisher (CNA): Fortinet, Inc. · Vendor: fortinet

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-06 09:15 UTCPublished CVE record published
2026-04-13Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-04-16Deadline CISA due date for US federal agencies to patch
2026-06-17 10:18 UTCUpdated Record last modified

fortinet forticlientems DOWNGRADE

Affected: 7.4.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.4.4

1. Check installed version

apt-cache policy forticlientems || rpm -q forticlientems || forticlientems --version

2. No fixed release: DOWNGRADE to a release before 7.4.4 (Debian / Ubuntu)

apt-cache madison forticlientems sudo apt install forticlientems=<VERSION_BEFORE_7.4.4> sudo apt-mark hold forticlientems

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list forticlientems sudo dnf downgrade forticlientems-<VERSION_BEFORE_7.4.4> sudo dnf versionlock add forticlientems

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · proftpd · FIXED · 1.3.9e-2.fc46 · FEDORA-2026-fcb0a25c2f · source

sudo dnf upgrade --advisory=FEDORA-2026-fcb0a25c2f

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: 0xBlackash/CVE-2026-21643 (18 stars)
GitHub PoC: alirezac0/CVE-2026-21643 (5 stars)
Write-up: github.com/0xBlackash/CVE-2026-21643/blob/main/cve-2026-21643.py
Nuclei scan template: Fortinet FortiClientEMS 7.4.4 - SQL Injection

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-21643?

forticlientems: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-21643 being exploited?

Yes. CVE-2026-21643 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-21643 affect?

CVE-2026-21643 affects forticlientems. Severity is critical (CVSS 9.8). 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 H

How urgent is CVE-2026-21643?

Priority 97/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Fortinet vulnerabilities

Related CVEs

CVE-2026-39809 MEDIUM 6.7 UPGRADE A improper neutralization of special elements used in an sql command ('sql injection') vulnerability in Fortin
CVE-2026-39810 MEDIUM 6.0 UPGRADE A use of hard-coded cryptographic key vulnerability in Fortinet FortiClientEMS 7.4.0 through 7.4.5 may allow a
CVE-2026-59836 HIGH 7.5 UPGRADE A improper certificate validation vulnerability in Fortinet FortiClientEMS 7.4.3 through 7.4.5, FortiClientEMS
CVE-2026-35616 CRITICAL 9.8 EXPLOITED DOWNGRADE Fortinet FortiClient EMS Improper Access Control Vulnerability
CVE-2025-59922 HIGH 7.2 UPGRADE An improper neutralization of special elements used in an SQL command ('SQL Injection') vulnerability [CWE-89]

References

← Back to latest CVEs