What products are affected by CVE-2026-35616?

CVE-2026-35616 affects Fortinet FortiClient EMS. Refer to the vendor advisory and NVD record for affected versions.

Is there a public exploit for CVE-2026-35616?

Yes. Public exploit code or proof-of-concept has been identified for CVE-2026-35616. This lowers the barrier for exploitation and increases the urgency of patching. Organizations should prioritize remediation immediately.

What is the EPSS score for CVE-2026-35616?

CVE-2026-35616 has an EPSS score of 34.8%, placing it in the 97th percentile. This means it has a 34.8% probability of being exploited in the next 30 days, higher than 97% of all known vulnerabilities. EPSS (Exploit Prediction Scoring System) is maintained by FIRST and uses real-world threat data to estimate exploitation likelihood.

Actively Exploited — CISA KEV

CVE-2026-35616: Fortinet FortiClient EMS Critical Vulnerability

Severity: Critical | CVSS 3.1: 9.8 | Published: 2026-04-04 | KEV Added: 2026-04-06

What is CVE-2026-35616?

A improper access control vulnerability in Fortinet FortiClientEMS 7.4.5 through 7.4.6 may allow an unauthenticated attacker to execute unauthorized code or commands via crafted requests.

Technical Analysis

Weakness Classification

This vulnerability is classified as CWE-284 — Improper Access Control. The software does not properly restrict access to resources, allowing unauthorized users to perform actions or access data.

Attack Vector Breakdown

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Impact Analysis

This vulnerability is exploitable over the network, meaning any system reachable via the internet or internal network is potentially at risk without physical access. The attack complexity is low, requires no special privileges, and needs no user interaction — making it straightforward to exploit at scale. Successful exploitation can result in full confidentiality breach (complete data disclosure), complete integrity compromise (data modification or code execution), total availability loss (denial of service). The software does not properly restrict access to resources, allowing unauthorized users to perform actions or access data.

Exploitation Probability (EPSS): 34.8% chance of exploitation in the next 30 days (97th percentile). This is a significantly elevated exploitation probability — prioritize patching.

Exploit Availability

Public exploit code or proof-of-concept is available for CVE-2026-35616. This significantly increases the risk of exploitation, as attackers can use or adapt existing exploit code rather than developing their own. A public exploit reference has been identified. Organizations should treat this as an urgent patching priority.

Is CVE-2026-35616 being exploited?

Yes. CVE-2026-35616 is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, restricted to CVEs with confirmed active exploitation in the wild. CISA added this vulnerability on 2026-04-06. Inclusion in KEV triggers the patching mandate under BOD 22-01 for U.S. federal civilian agencies, with a remediation deadline of 2026-04-09. Additionally, public exploit code is available, which lowers the barrier for attackers.

How to fix CVE-2026-35616

Upgrade FortiOS or the affected product firmware to the fixed version listed in the FortiGuard PSIRT advisory. For FortiGate devices, use the firmware upgrade path tool to determine the correct upgrade sequence. If immediate patching is not possible, apply the recommended workaround (e.g. disabling affected features, restricting management interface access). Check the Fortinet PSIRT Advisories page for the specific patch or update. CISA's Known Exploited Vulnerabilities catalog requires U.S. federal agencies to remediate this vulnerability by the due date shown below under Binding Operational Directive 22-01. Private organizations should treat KEV entries as priority-one patches because active exploitation has been confirmed in the wild.

Related Vulnerabilities

Other actively exploited vulnerabilities affecting FortiClient EMS or sharing the same weakness (CWE-284):

CVE-2026-21643 (Critical 9.8) [same product] — An improper neutralization of special elements used in an sql command ('sql…
CVE-2026-24858 (Critical 9.8) [same vendor] — An Authentication Bypass Using an Alternate Path or Channel vulnerability…
CVE-2025-59718 (Critical 9.8) [same vendor] — A improper verification of cryptographic signature vulnerability in Fortinet…
CVE-2025-58034 (High 7.2) [same vendor] — An Improper Neutralization of Special Elements used in an OS Command ('OS…
CVE-2025-64446 (Unknown N/A) [same vendor] — Fortinet FortiWeb contains a relative path traversal vulnerability that may…

Frequently asked questions

Is CVE-2026-35616 critical?

CVE-2026-35616 has a CVSS 3.1 base score of 9.8 — Critical severity. It should be treated as a priority patch, especially given the active exploitation confirmed by CISA. The availability of public exploit code further increases the urgency.

Is CVE-2026-35616 being actively exploited?

Yes — CISA added CVE-2026-35616 to the Known Exploited Vulnerabilities catalog on 2026-04-06. Inclusion in KEV means CISA has confirmed in-the-wild exploitation. Public exploit code has also been identified, making exploitation accessible to a broader range of threat actors.

How do I patch CVE-2026-35616?

Apply the security update from Fortinet for FortiClient EMS. Federal agencies must remediate by 2026-04-09 under BOD 22-01. Refer to the Fortinet PSIRT Advisories for the official patch.

What type of vulnerability is CVE-2026-35616?

CVE-2026-35616 is classified under CWE-284 (Improper Access Control). The software does not properly restrict access to resources, allowing unauthorized users to perform actions or access data.

What is the CVSS score for CVE-2026-35616?

CVE-2026-35616 has a CVSS 3.1 base score of 9.8, classifying it as Critical severity. The attack vector is Network, attack complexity is Low, and no privileges are required.