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

> Unauthenticated attackers can brute-force predictable attachment tokens to download private files from FreeScout help desk instances.

- **Severity:** High 8.8 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Apr 2026
- **Updated:** 21 Apr 2026
- **Also known as:** GHSA-2783-wxmm-wmwr

## What is CVE-2026-40496?

CVE-2026-40496 is a high-severity vulnerability in freescout-help-desk freescout, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-340 (Generation of Predictable Numbers or Identifiers), CWE-330 (Use of Insufficiently Random Values)

## Which versions are affected by CVE-2026-40496?

It affects 1 product.


Products: Freescout Freescout.

## How do I fix CVE-2026-40496?

No fix has been published for CVE-2026-40496 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-40496 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40496 exists.

## Other vulnerabilities in freescout-help-desk freescout

- [CVE-2026-28289](https://insights.sbomify.com/CVE-2026-28289/): FreeScout 1.8.206 Patch Bypass for CVE-2026-27636 via Zero-Width Space Character Leads to Remote Code Execution (critical 10.0)
- [CVE-2026-27637](https://insights.sbomify.com/CVE-2026-27637/): FreeScout's Predictable Authentication Token Enables Account Takeover (critical 9.8)
- [CVE-2026-32754](https://insights.sbomify.com/CVE-2026-32754/): FreeScout: Stored XSS via Unescaped Email Template Rendering ({!! $thread->body !!}) (critical 9.3)
- [CVE-2024-29185](https://insights.sbomify.com/CVE-2024-29185/): FreeScout OS Command Injection vulnerability (critical 9.1)
- [CVE-2026-40498](https://insights.sbomify.com/CVE-2026-40498/): FreeScout has Authentication Bypass and Information Disclosure in SystemController via /system/cron (high 8.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40496 and fix it if it is affected.

What it is: CVE-2026-40496 is a high-severity vulnerability in freescout-help-desk freescout, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40496 exists.

Affected product: freescout-help-desk freescout. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-40496/ (Markdown: https://insights.sbomify.com/CVE-2026-40496/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40496
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40496
- OSV: https://osv.dev/vulnerability/CVE-2026-40496

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40496/
Summaries are generated and may contain mistakes; the official description above is the record.