# CVE-2026-40591

> Vulnerability · severity: **HIGH** (CVSS 7.1).

## Description

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.214, the phone-conversation creation flow accepts attacker-controlled `customer_id`, `name`, `to_email`, and `phone` values and resolves the target customer in the backend without enforcing mailbox-scoped customer visibility. As a result, a low-privileged agent who can create a phone conversation in Mailbox A can bind the new Mailbox A phone conversation to a hidden customer from Mailbox B and add a new alias email to that hidden customer record by supplying `to_email`. Version 1.8.214 fixes the vulnerability.

## Key facts

- **CVE ID:** CVE-2026-40591
- **Published:** 2026-04-21
- **CVSS severity:** HIGH
- **CVSS base score:** 7.1
- **CWE codes:** CWE-639

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40591

## Citation

> AI Analytics. CVE-2026-40591. Retrieved 2026-07-09 from https://api.ai-analytics.org/cve/CVE-2026-40591. Derived from NIST NVD. Licensed CC0.

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