5.8
MEDIUM CVSS 3.1
CVE-2026-40567
FreeScout has HTML Injection in Outgoing Emails via Unsanitized Customer Name in Signature Variables
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.

INFO

Published Date :

April 21, 2026, 5:16 p.m.

Last Modified :

April 21, 2026, 5:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-40567 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update FreeScout to version 1.8.213 or later to fix email injection vulnerability.
  • Update FreeScout to version 1.8.213.
  • Verify all outgoing emails are sanitized.
  • Review and sanitize existing email content.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-40567 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-40567 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-40567 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-40567 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 21, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
    Added CWE CWE-116
    Added Reference https://github.com/freescout-help-desk/freescout/commit/9131b16f80eade81002cb9809a2603f6b61981cf
    Added Reference https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213
    Added Reference https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.