CVE-2026-40589
FreeScout has Customer Edit Cross-Mailbox Email Takeover
Description
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.
INFO
Published Date :
April 21, 2026, 5:16 p.m.
Last Modified :
April 21, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-40589
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update FreeScout to version 1.8.214.
- Review access controls for agent permissions.
- Verify customer data integrity after update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40589.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40589 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40589
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40589 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40589 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Apr. 21, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L Added CWE CWE-639 Added Reference https://github.com/freescout-help-desk/freescout/commit/2e2fe37111d92ac665b9ad8806eac94a1a3e502c Added Reference https://github.com/freescout-help-desk/freescout/releases/tag/1.8.214 Added Reference https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-mv55-3mgv-fxwr