CVE-2026-40589

FreeScout has Customer Edit Cross-Mailbox Email Takeover

7.6 High

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: High
Availability: Low

Exploit likelihood

0.24%Up 0.2 points since Apr 22, 2026

What each source reports

CVE List Score used 7.6

FreeScout has Customer Edit Cross-Mailbox Email Takeover

Record: CVE-2026-40589
CVSS 3.1: 7.6 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L
Weakness: CWE-639
Updated: 2026-11-02

EUVDEUVD-2026-24184 7.6

Record: EUVD-2026-24184
CVSS 3.1: 7.6 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L
Updated: 2026-11-02

NVD 7.6

Record: CVE-2026-40589
CVSS 3.1: 7.6 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L
Weakness: CWE-639
Updated: 2026-11-02

OSV 7.6

FreeScout has Customer Edit Cross-Mailbox Email Takeover

Record: CVE-2026-40589
CVSS 3.1: 7.6 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L
Weakness: CWE-639
Updated: 2026-11-02

Affected products

freescout-help-desk freescout

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-40589 is a high vulnerability (CVSS 7.6) in Freescout-help-desk Freescout, published April 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.24%, the 14th percentile. No source names a fixed version.