CVE-2026-40589 HIGH

CVE-2026-40589: FreeScout has Customer Edit Cross-Mailbox Email Takeover

Vendor Freescout-Help-Desk

Product freescout

Weakness CWE-639 · IDOR

Published April 21, 2026

Last update April 21, 2026

View on NVD All CVEs

CVSS base score

7.6/10

Attack vector Network

Attack complexity Low

Privileges required Low

User interaction None

Confidentiality Low

Integrity High

CVSS vector

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

What the vulnerability does

01Description

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.214, a low-privileged agent can edit a visible customer and add an email address already owned by a hidden customer in another mailbox. The server discloses the hidden customer’s name and profile URL in the success flash, reassigns the hidden email to the visible customer, and rebinds hidden-mailbox conversations for that email to the visible customer. Version 1.8.214 fixes the issue.

Key dates

02Disclosure timeline

April 21, 2026 CVE published

April 21, 2026 Record updated

External resources

03References

NVD — National Vulnerability Database https://nvd.nist.gov/vuln/detail/CVE-2026-40589 CWE — Common Weakness Enumeration https://cwe.mitre.org/data/definitions/639.html