{"id":"CVE-2026-40566","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-40566","generatedAt":"2026-10-28T10:36:41.773Z","title":"Versions prior to 1.8.213 have a Server-Side Request Forgery (SSRF) vulnerability in the IMAP/SMTP connection test functionality of FreeScout's `MailboxesController`.","description":"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 `MailboxesController`. Three AJAX actions  `fetch_test` (line 731), `send_test` (line 682), and `imap_folders` (line 773) in `app/Http/Controllers/MailboxesController.php`  pass admin-configured `in_server`/`in_port` and `out_server`/`out_port` values directly to `fsockopen()` via `Helper::checkPort()` 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 `sanitizeRemoteUrl()` or `checkUrlIpAndHost()` functions. The validation block in `connectionIncomingSave()` 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 `fsockopen()`) 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 `log` field, making this a semi-blind SSRF that enables service fingerprinting. In cloud environments, the metadata endpoint at `169[.]254[.]169[.]254` can be probed and partial response data may be leaked through protocol error messages. This is distinct from the `sanitizeRemoteUrl()` redirect bypass (freescout-3) -- different code path, different root cause, different protocol layer. Version 1.8.213 patches the vulnerability.","published":"2026-04-21T17:16:55.000Z","lastModified":"2026-06-17T10:45:28.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":4.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N"},"cwe":["CWE-918"],"affected":[],"epss":{"score":0.00291,"percentile":0.21581,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.29%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/freescout-help-desk/freescout/commit/efe82e31b4a0d4c0b20025d09df0615e8139ff08","source":"security-advisories@github.com"},{"url":"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213","source":"security-advisories@github.com"},{"url":"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-rgx6-8x4g","source":"security-advisories@github.com"},{"url":"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-rgx6-8x4g","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-40566","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}