Fortinet Patches Actively Exploited CVE-2026
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2026-21643 | Unauthenticated SQL Injection to Code Execution in Fortinet FortiClient EMS 7.4.4 CVE-2026-21643 is a critical SQL injection flaw (CWE-89, improper neutralization of special elements used in an SQL command) in Fortinet FortiClient EMS 7.4.4, scored 9.8 critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). An unauthenticated remote attacker can trigger it by sending specifically crafted HTTP requests to the EMS server, and successful injection allows execution of unauthorized code or commands, yielding high confidentiality, integrity, and availability impact. Any organization running the affected FortiClient EMS release is exposed, with internet-facing EMS management servers at greatest risk. Exploitation is confirmed: CISA added the flaw to the Known Exploited Vulnerabilities catalog on 2026-04-13, EPSS assigns a 94.1% probability of exploitation within 30 days (99.9th-plus percentile), and news reports describe active zero-day exploitation that prompted Fortinet to issue emergency patches, alongside related FortiClient EMS hotfixes (CVE-2026-35616). Do: Upgrade affected FortiClient EMS 7.4.4 deployments using the emergency patch/hotfix Fortinet has released (see the Fortinet PSIRT advisory for fixed builds), prioritizing internet-exposed EMS servers; federal agencies must satisfy the BOD 22-01 requirement per the KEV listing. Until patched, restrict public exposure of the EMS web interface and review web access and database logs for signs of crafted HTTP requests or unexpected command execution. | 9.8 | 94% | KEV PoC |
| largeon the order of tens of thousands of FortiClient EMS server deployments (estimate) | |
| CVE-2026-35616 | Unauthenticated Code Execution in Fortinet FortiClient EMS 7.4.5–7.4.6 Fortinet FortiClient EMS versions 7.4.5 through 7.4.6 contain an improper access control flaw (CWE-284) that allows an unauthenticated attacker to execute unauthorized code or commands by sending crafted requests over the network. The attack requires no authentication, privileges, or user interaction, making any reachable EMS management server a direct target. A successful attacker gains code execution on the EMS host, and reported campaigns have used the flaw to deploy a credential stealer. Any organization running FortiClient EMS 7.4.5 or 7.4.6 is affected. The flaw is being exploited in the wild: it was added to CISA KEV on 2026-04-06, carries a 90.7% EPSS probability of exploitation within 30 days, and Fortinet has released emergency hotfixes. Do: Upgrade FortiClient EMS off 7.4.5/7.4.6 using the fixed release or emergency hotfix per Fortinet's advisory (the available data does not specify the fixed version number), prioritizing internet-exposed servers; U.S. federal agencies must follow BOD 22-01. Until patched, restrict EMS management access to trusted networks or VPN and monitor for credential-stealer activity on managed endpoints. Given confirmed in-the-wild exploitation, assume possible compromise and hunt for indicators on both EMS hosts and endpoints it manages. | 9.8 | 91% | KEV |
| large≈10,000–100,000 EMS deployments (order-of-magnitude estimate; exact counts not in the data) |
Full article472 words · extracted from thehackernews.com · click to collapse
Ravie LakshmananApr 05, 2026Vulnerability / API Security
Fortinet has released out-of-band patches for a critical security flaw impacting FortiClient EMS that it said has been exploited in the wild.
The vulnerability, tracked as CVE-2026-35616 (CVSS score: 9.1), has been described as a pre-authentication API access bypass leading to privilege escalation.
"An improper access control vulnerability [CWE-284] in FortiClient EMS may allow an unauthenticated attacker to execute unauthorized code or commands via crafted requests," Fortinet said in a Saturday advisory.
The issue affects FortiClient EMS versions 7.4.5 through 7.4.6. It's expected to be fully patched in the upcoming version 7.4.7, although the company has released a hotfix to address it.
Simo Kohonen from Defused Cyber and Nguyen Duc Anh have been credited with discovering and reporting the flaw. In a post on X, Defused Cyber said it observed zero-day exploitation of CVE-2026-35616 earlier this week. According to watchTowr, exploitation attempts against CVE-2026-35616 were first recorded against its honeypots on March 31, 2026.
Successful exploitation of the flaw could allow an unauthenticated attacker to sidestep API authentication and authorization protections, and execute malicious code or commands via crafted requests.
"Fortinet has observed this to be exploited in the wild and urges vulnerable customers to install the hotfix for FortiClient EMS 7.4.5 and 7.4.6," the company added.
The development comes merely days after another recently-patched, critical vulnerability in FortiClient EMS (CVE-2026-21643, CVSS score: 9.1) came under active exploitation. It's currently not known if the same threat actor is behind the exploitation of both the flaws, and if they are being weaponized together.
Given the severity of the vulnerabilities, users are advised to update their FortiClient EMS to the latest version as soon as possible.
"The timing of the ramp-up of in-the-wild exploitation of this zero-day is likely not coincidental," watchTowr CEO and founder Benjamin Harris told The Hacker News.
"Attackers have shown repeatedly that holiday weekends are the best time to move. Security teams are at half strength, on-call engineers are distracted, and the window between compromise and detection stretches from hours to days. Easter, like any other holiday, represents opportunity."
"What is disappointing is the bigger picture. This is the second unauthenticated vulnerability in FortiClient EMS in a matter of weeks."
"So, once again, organizations running FortiClient EMS and exposed to the Internet should treat this as an emergency response situation, not something to pick up on Tuesday morning. Apply the hotfix. Attackers already have a head start."
Update
The U.S. Cybersecurity and Infrastructure Security Agency (CISA), on April 6, 2026, added CVE-2026-35616 to its Known Exploited Vulnerabilities (KEV) catalog, requiring Federal Civilian Executive Branch (FCEB) agencies to apply the necessary fixes by April 9, 2026.
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Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2026/04/fortinet-patches-actively-exploited-cve.html