FreeScout: Improper Authorization in Phone Conversation Creation Enables Cross-Mailbox Hidden Customer Modification
Summary
| CVE | CVE-2026-40591 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-21 17:16:56 UTC |
| Updated | 2026-04-21 18:16:51 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.1 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
Problem Types: CWE-639 | CWE-639 CWE-639: Authorization Bypass Through User-Controlled Key
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N |
| 3.1 | CNA | DECLARED | 7.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
HighAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Freescout-help-desk | Freescout | affected < 1.8.214 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/freescout-help-desk/freescout/security/advisories/GHSA-9ff4-m... | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| github.com/freescout-help-desk/freescout/commit/83eea1ca47d97c6cdc90c501... | [email protected] | github.com | |
| github.com/freescout-help-desk/freescout/releases/tag/1.8.214 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.