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Vulnerabilities

Vulnerability · CVE-2026-40569

FreeScout is a free self-hosted help desk and shared mailbox.

Published Apr 21, 2026 · catalog updated Jun 17, 2026 · FreeScout is a free

Check if you run it

No confirmed exploitation is on record for CVE-2026-40569. EPSS is 0.52%. Act only if a listed version of FreeScout is a free is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (FreeScout is a free).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.0
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.52%
Remediation
Advisory link
Affected products
See sources for product scope

FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a mass assignment vulnerability in the mailbox connection settings endpoints of FreeScout ( at and at line 398). Both methods pass directly to without any field allowlisting, allowing an authenticated admin to overwrite any of the 32 fields in the Mailbox model's array -- including security-critical fields that do not belong to the connection settings form, such as , , , , , and . Validation in is entirely commented out, and the validator in only checks value formats for SMTP fields without stripping extra parameters. An authenticated admin user can exploit this by appending hidden parameters (e.g., ) to a legitimate connection settings save request. Because the field is not displayed on the connection settings form (it only appears on the general mailbox settings page), the injection is invisible to other administrators reviewing connection settings. Once set, every outgoing email from the affected mailbox is silently BCC'd to the attacker via the job. The same mechanism allows redirecting outgoing SMTP through an attacker-controlled server, injecting tracking pixels or phishing links into email signatures, and enabling attacker-crafted auto-replies -- all from a single HTTP request. This is particularly dangerous in multi-admin environments where one admin can silently surveil mailboxes managed by others, and when an admin session is compromised via a separate vulnerability (e.g., XSS), the attacker gains persistent email exfiltration that survives session expiry. Version 1.8.213 fixes the issue.

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2026-40569

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-40569. EPSS is 0.52%. Act only if a listed version of FreeScout is a free is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-284: Improper Access Control; CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes. EPSS 0.52%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 21, 2026 · NIST NVD

    Detected

    FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a mass assignment vulnerability in the mailbox connection settings endpoints of FreeScout ( at and at line 398). Both methods pass directly to without any field allowlisting, allowing an authenticated admin to overwrite any of the 32 fields in the Mailbox model's array -- including security-critical fields

  2. Jun 17, 2026 · NIST NVD

    Updated

    FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a mass assignment vulnerability in the mailbox connection settings endpoints of FreeScout ( at and at line 398). Both methods pass directly to without any field allowlisting, allowing an authenticated admin to overwrite any of the 32 fields in the Mailbox model's array -- including security-critical fields

Sources

  • CVE.orgVulnerability recordCVE-2026-40569

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-40569

    30-day exploitation probability 0.5%

    first.org
  • NIST NVDVulnerability recordCVE-2026-40569

    FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a mass assignment vulnerability in the mailbox connection settings endpoints of FreeScout ( at and `connection

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.