# CVE-2026-47123: FreeScout: Agent Impersonation via Missing HMAC Verification on Notification Reply Message-ID Path

> Attackers can impersonate agents by spoofing email headers due to missing HMAC verification, injecting messages forwarded to customers.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/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:** 29 May 2026
- **Updated:** 2 Jun 2026
- **Also known as:** GHSA-6r38-6mcf-2ww3

## What is CVE-2026-47123?

CVE-2026-47123 is a high-severity authentication bypass vulnerability in freescout-help-desk freescout, published on 29 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to 1.8.220, the email processing pipeline in FreeScout's FetchEmails command has two code paths for identifying agent (user) replies based on In-Reply-To / References headers. The notification reply path (notify-{thread_id}-{user_id}-...) extracts thread_id and user_id directly from the Message-ID without HMAC verification. An external attacker who can spoof the From address of a helpdesk agent can inject messages that FreeScout processes as legitimate agent replies — which are then automatically forwarded to customers via the legitimate SMTP server. This vulnerability is fixed in 1.8.220.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity), CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-47123?


## How do I fix CVE-2026-47123?

No fix has been published for CVE-2026-47123 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-47123 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47123 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47123 and fix it if it is affected.

What it is: CVE-2026-47123 is a high-severity authentication bypass vulnerability in freescout-help-desk freescout, published on 29 May 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-2026-47123 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-2026-47123/ (Markdown: https://insights.sbomify.com/CVE-2026-47123/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47123
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47123
- OSV: https://osv.dev/vulnerability/CVE-2026-47123

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47123/
Summaries are generated and may contain mistakes; the official description above is the record.