CVE-2026-40496

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

State: Published
Severity: 8.8 High
Published: Apr 21, 2026
Updated: Apr 21, 2026
Reserved: Apr 13, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	8.8 High	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	GitHub_M

Weaknesses

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

Affected Products

Product	Versions
freescoutfreescout-help-desk	< 1.8.213Affected

References

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