# CVE-2026-40567: FreeScout has HTML Injection in Outgoing Emails via Unsanitized Customer Name in Signature Variables

> Unauthenticated attackers can inject HTML into outgoing support emails via crafted sender names, enabling phishing and tracking pixel attacks.

- **Severity:** Medium 5.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N`)
- **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-q8v4-v62h-5528

## What is CVE-2026-40567?

CVE-2026-40567 is a medium-severity cross-site scripting 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, an unauthenticated attacker can inject arbitrary HTML into outgoing emails generated by FreeScout by sending an email with a crafted From display name. The name is stored in the database without sanitization and rendered unescaped into outgoing reply emails via the `{%customer.fullName%}` signature variable. This allows embedding phishing links, tracking pixels, and spoofed content inside legitimate support emails sent from the organization's address. Version 1.8.213 fixes the issue.

Weakness: CWE-116 (Improper Encoding or Escaping of Output)

## Which versions are affected by CVE-2026-40567?


## How do I fix CVE-2026-40567?

No fix has been published for CVE-2026-40567 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-40567 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40567 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40567 and fix it if it is affected.

What it is: CVE-2026-40567 is a medium-severity cross-site scripting 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-2026-40567 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-2026-40567/ (Markdown: https://insights.sbomify.com/CVE-2026-40567/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40567
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40567
- OSV: https://osv.dev/vulnerability/CVE-2026-40567

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40567/
Summaries are generated and may contain mistakes; the official description above is the record.