Vulnerability · Published Apr 21, 2026 · Assigned by GitHub_M

CVE-2026-40496FreeScout has Predictable Attachment Token that Allows Unauthenticated Private File Download via Brute Force

High 8.8

In plain English

A high-severity weak randomness 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 0.4% (higher than 35% of all known vulnerabilities).

Severity (CVSS 4.0)8.8High

Exploit odds (30 days)0.4%top 65.2% 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 1.8.213, 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.

Affected products (as reported)

Vendor	Product	Versions
freescout-help-desk	freescout	< 1.8.213

Weakness: CWE-330, CWE-340 · 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

References

https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-2783-wxmm-wmwr x_refsource_CONFIRM
https://github.com/freescout-help-desk/freescout/commit/dbdf8f2260b43a21818255c70f0b61b9de9cd555 x_refsource_MISC
https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213 x_refsource_MISC