CVE-2026-40590 MEDIUM

CVE-2026-40590: FreeScout's Customer AJAX Create Modifies Hidden Existing Customer

Vendor Freescout-Help-Desk
Product freescout
Weakness CWE-639 · IDOR
Published April 21, 2026
Last update April 21, 2026

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

What the vulnerability does

01Description

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.214, the Change Customer modal exposes a “Create a new customer” flow via POST /customers/ajax with action=create. Under limited visibility, the endpoint drops unique-email validation. If the supplied email already belongs to a hidden customer, Customer::create() reuses that hidden customer object and fills empty profile fields from attacker-controlled input. Version 1.8.214 fixes the vulnerability.

Key dates

02Disclosure timeline

April 21, 2026 CVE published
April 21, 2026 Record updated