CVE-2026-40496 PUBLISHED

FreeScout has Predictable Attachment Token that Allows Unauthenticated Private File Download via Brute Force

Assigner: GitHub_M
Reserved: 13.04.2026 Published: 21.04.2026 Updated: 21.04.2026

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, attachment download tokens are generated using a weak and predictable formula: md5(APP_KEY + attachment_id + size). Since attachment_id is sequential and size can be brute-forced in a small range, an unauthenticated attacker can forge valid tokens and download any private attachment without credentials. Version 1.8.213 fixes the issue.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
CVSS Score: 8.8

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	freescout-help-desk
Product	freescout
Versions	Version < 1.8.213 is affected

References

Problem Types

CWE-330: Use of Insufficiently Random Values CWE
CWE-340: Generation of Predictable Numbers or Identifiers CWE