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Vulnerabilities

Vulnerability · CVE-2026-40566

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-2026-40566. EPSS is 0.40%. 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
Medium4.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.40%
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 Server-Side Request Forgery (SSRF) vulnerability in the IMAP/SMTP connection test functionality of FreeScout's . Three AJAX actions (line 731), (line 682), and (line 773) in pass admin-configured / and / values directly to via and to IMAP/SMTP client connections with zero SSRF protection. There is no IP validation, no hostname restriction, no blocklist of internal ranges, and no call to the project's own or functions. The validation block in is entirely commented out. An authenticated admin can configure a mailbox's IMAP or SMTP server to point at any internal host and port, then trigger a connection test. The server opens raw TCP connections (via ) and protocol-level connections (via IMAP client or SMTP transport) to the attacker-specified target. The response differentiates open from closed ports, enabling internal network port scanning. When the IMAP client connects to a non-IMAP service, the target's service banner or error response is captured in the IMAP debug log and returned in the AJAX response's field, making this a semi-blind SSRF that enables service fingerprinting. In cloud environments, the metadata endpoint at can be probed and partial response data may be leaked through protocol error messages. This is distinct from the redirect bypass (freescout-3) -- different code path, different root cause, different protocol layer. Version 1.8.213 patches the vulnerability.

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

How to fix CVE-2026-40566

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-2026-40566. EPSS is 0.40%. 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-918: Server-Side Request Forgery (SSRF). EPSS 0.40%. 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 Server-Side Request Forgery (SSRF) vulnerability in the IMAP/SMTP connection test functionality of FreeScout's . Three AJAX actions (line 731), (line 682), and (line 773) in pass admin-configured / and / values directly to via and to IMAP/SMTP client connections with zero SSRF protection. There is no IP

  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 Server-Side Request Forgery (SSRF) vulnerability in the IMAP/SMTP connection test functionality of FreeScout's . Three AJAX actions (line 731), (line 682), and (line 773) in pass admin-configured / and / values directly to via and to IMAP/SMTP client connections with zero SSRF protection. There is no IP

Sources

  • CVE.orgVulnerability recordCVE-2026-40566

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-40566

    30-day exploitation probability 0.4%

    first.org
  • NIST NVDVulnerability recordCVE-2026-40566

    FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a Server-Side Request Forgery (SSRF) vulnerability in the IMAP/SMTP connection test functionality of FreeScout's . Three AJAX actions (line 731), `send_

    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.