Vulnerability · Published Apr 21, 2026 · Assigned by GitHub_M

CVE-2026-40590FreeScout's Customer AJAX Create Modifies Hidden Existing Customer

Medium 4.3

In plain English

A medium-severity authorization bypass via user-controlled key in freescout from freescout-help-desk. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.2%top 88.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.214, the Change Customer modal exposes a “Create a new customer” flow via POST /customers/ajax with action=create. Under limited visibility, the endpoint drops unique-email validation. If the supplied email already belongs to a hidden customer, Customer::create() reuses that hidden customer object and fills empty profile fields from attacker-controlled input. Version 1.8.214 fixes the vulnerability.

Affected products (as reported)

Vendor	Product	Versions
freescout-help-desk	freescout	< 1.8.214

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-wjw4-8xg6-342m x_refsource_CONFIRM
https://github.com/freescout-help-desk/freescout/commit/b3d7611e6e173ed8a5e525b791deb6b32cf1ce62 x_refsource_MISC
https://github.com/freescout-help-desk/freescout/releases/tag/1.8.214 x_refsource_MISC