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

Severity: high (CVSS 7.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-21 · updated 2026-06-17
Weakness: CWE-639

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.

Affected products

freescout-help-desk freescout: before 1.8.214

References

https://github.com/freescout-help-desk/freescout/commit/2e2fe37111d92ac665b9ad8806eac94a1a3e502c
https://github.com/freescout-help-desk/freescout/releases/tag/1.8.214
https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-mv55-3mgv-fxwr
https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-mv55-3mgv-fxwr

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