CVE-2026-40496

HIGH8.8

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

Published Apr 21, 2026

Modified 2 days ago

Details

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.

References

WEB

https://github.com/freescout-help-desk/freescout/commit/dbdf8f2260b43a21818255c70f0b61b9de9cd555

WEB

https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213

WEB

https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-2783-wxmm-wmwr

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-40496

CVSS Analysis

CVSS v4.0

8.8