CVE-2026-40496CWE-330CWE-340

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

High · published April 21, 2026

CVSS v4.0
8.8
EPSS
1%
Percentile
45.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.8 · HIGH
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
EPSS
0.00545 · 45.0th percentile
Weaknesses
CWE-330 · Use of Insufficiently Random Values; CWE-340 · Generation of Predictable Numbers or Identifiers
Published
2026-04-21T01:38Z
EPSS history
Timeline
  • 21 APR 01:38Z
    FreeScout has Predictable Attachment Token that Allows Unauthenticated Private File Download via Brute Force
    cvelistv5