What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 4.3 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, 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

• freescout-help-desk freescout: before 1.8.214

References

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

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