{"api_version":"1","generated_at":"2026-04-21T20:55:41+00:00","cve":"CVE-2026-40566","urls":{"html":"https://cve.report/CVE-2026-40566","api":"https://cve.report/api/cve/CVE-2026-40566.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-40566","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-40566"},"summary":{"title":"FreeScout vulnerable to SSRF via IMAP/SMTP Connection Test Endpoints","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.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-04-21 17:16:55","updated_at":"2026-04-21 18:16:50"},"problem_types":["CWE-918","CWE-918 CWE-918: Server-Side Request Forgery (SSRF)"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","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","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N","baseScore":4.1,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"HIGH","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"DECLARED","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","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.1,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"HIGH","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N","version":"3.1"}}],"references":[{"url":"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-rgx6-8x4g","name":"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-rgx6-8x4g","refsource":"134c704f-9b21-4f2e-91b3-4a467353bcc0","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213","name":"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/freescout-help-desk/freescout/commit/efe82e31b4a0d4c0b20025d09df0615e8139ff08","name":"https://github.com/freescout-help-desk/freescout/commit/efe82e31b4a0d4c0b20025d09df0615e8139ff08","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-40566","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40566","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"freescout-help-desk","product":"freescout","version":"affected < 1.8.213","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-40566","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-04-21T17:33:06.910770Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-04-21T17:33:11.528Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"references":[{"tags":["exploit"],"url":"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-rgx6-8x4g"}],"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"product":"freescout","vendor":"freescout-help-desk","versions":[{"status":"affected","version":"< 1.8.213"}]}],"descriptions":[{"lang":"en","value":"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."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.1,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"HIGH","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","description":"CWE-918: Server-Side Request Forgery (SSRF)","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-04-21T16:04:35.587Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-rgx6-8x4g","tags":["x_refsource_CONFIRM"],"url":"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-rgx6-8x4g"},{"name":"https://github.com/freescout-help-desk/freescout/commit/efe82e31b4a0d4c0b20025d09df0615e8139ff08","tags":["x_refsource_MISC"],"url":"https://github.com/freescout-help-desk/freescout/commit/efe82e31b4a0d4c0b20025d09df0615e8139ff08"},{"name":"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213","tags":["x_refsource_MISC"],"url":"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213"}],"source":{"advisory":"GHSA-fg98-rgx6-8x4g","discovery":"UNKNOWN"},"title":"FreeScout vulnerable to SSRF via IMAP/SMTP Connection Test Endpoints"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-40566","datePublished":"2026-04-21T16:04:35.587Z","dateReserved":"2026-04-14T13:24:29.474Z","dateUpdated":"2026-04-21T17:33:11.528Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-21 17:16:55","lastModifiedDate":"2026-04-21 18:16:50","problem_types":["CWE-918","CWE-918 CWE-918: Server-Side Request Forgery (SSRF)"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N","baseScore":4.1,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"HIGH","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":2.3,"impactScore":1.4}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"40566","Ordinal":"1","Title":"FreeScout vulnerable to SSRF via IMAP/SMTP Connection Test Endpo","CVE":"CVE-2026-40566","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"40566","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"FreeScout vulnerable to SSRF via IMAP/SMTP Connection Test Endpo"}]}}}