CyberSecBulletin
CVE-2026-59841NVD status: Analyzed

FortiSIEMWindowsAgent: Improper Restriction of Communication Channel to Intended Endpoints

Published Updated By the CyberSecBulletin desk

CVE-2026-59841 is a high-severity improper restriction of communication channel to intended endpoints vulnerability in FortiSIEMWindowsAgent from Fortinet, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected FortiSIEMWindowsAgent versions: 7.4.0 through 7.4.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Fortisiem to 7.4.2 or a later version.
  2. Read the advisory on fortiguard.fortinet.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
FortinetFortiSIEMWindowsAgent7.4.0 through 7.4.1Not stated
FortinetFortisiem7.4.0 up to, but not including, 7.4.27.4.2

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (fortinet.com).

Official description

A improper restriction of communication channel to intended endpoints vulnerability in Fortinet FortiSIEMWindowsAgent 7.4.0 through 7.4.1 may allow attacker to escalation of privilege via <insert attack vector here>

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Restriction of Communication Channel to Intended Endpoints

The product establishes a communication channel to (or from) an endpoint for privileged or protected operations, but it does not properly ensure that it is communicating with the correct endpoint.

More Improper Restriction of Communication Channel to Intended Endpoints vulnerabilities (CWE-923)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Restriction of Communication Channel to Intended Endpoints vulnerabilities

Spotted an error? Tell us.