{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.8.213"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "efe82e31b4a0d4c0b20025d09df0615e8139ff08"
            },
            {
              "fixed": "acf57a7a4b19544641523c6f7e51b1035c03c9b6"
            }
          ],
          "repo": "https://github.com/freescout-help-desk/freescout",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-fg98-rgx6-8x4g"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40566.json"
  },
  "details": "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.",
  "id": "CVE-2026-40566",
  "modified": "2026-07-15T01:49:22.222293844Z",
  "published": "2026-04-21T16:04:35.587Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40566.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-rgx6-8x4g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40566"
    },
    {
      "type": "FIX",
      "url": "https://github.com/freescout-help-desk/freescout/commit/efe82e31b4a0d4c0b20025d09df0615e8139ff08"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "FreeScout vulnerable to SSRF via IMAP/SMTP Connection Test Endpoints"
}