# CVE-2026-62851: FreeScout: Cross-mailbox conversation existence / internal-id disclosure via the search-by-number (`#`) shortcut (missing mailbox authorization)

Status: published. Published: 2026-11-06. Updated: 2026-11-09.

FreeScout is a self-hosted help desk and shared mailbox. Prior to 1.8.226, the search-by-number shortcut in ConversationsController::search() resolves a user-controlled ticket number without applying the mailbox filter or view policy used by the normal search path. An authenticated non-admin agent who is a member of at least one mailbox can request /search with a hash-prefixed ticket number and use the 302 Location header to confirm that a conversation exists in a different mailbox the agent cannot access and learn its internal conversation and folder identifiers. The destination conversation remains protected, so this issue does not disclose message content, attachments, or customer data. This issue is fixed in version 1.8.226.

## Remediation

- fix: freescout-help-desk/freescout (self-hosted): GitHub reports patched versions 1.8.226. Check the advisory for the affected release branch. (source: GitHub GHSA-wqq7-4q7m-273v) — https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-wqq7-4q7m-273v

## Affected products and versions

- freescout-help-desk / freescout: < 1.8.226 (affected). Source: CNA: GitHub_M
-  / freescout-help-desk/freescout (freescout-help-desk/freescout): <1.8.226 (affected, GitHub advisory range). Source: GitHub GHSA-wqq7-4q7m-273v

## Severity and prioritization

- CVSS 3.1: 4.3 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N; source: CNA: GitHub_M

- CVSS 3.1: 4.3 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.19% as of 2026-11-09; percentile 8.99%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-200, CWE-639

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-wqq7-4q7m-273v (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/freescout-help-desk/freescout/commit/4e197d8ce97eb6610ef71402d8c2512824a9a1b5 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/freescout-help-desk/freescout/releases/tag/1.8.226 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/freescout-help-desk/freescout/commit/4e197d8ce97eb6610ef71402d8c2512824a9a1b5 (security-advisories@github.com)

- https://github.com/freescout-help-desk/freescout/releases/tag/1.8.226 (security-advisories@github.com)

- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-wqq7-4q7m-273v (security-advisories@github.com)

- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-wqq7-4q7m-273v (GitHub Security Advisories; advisory)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-62851; retrieved 2026-11-09; source updated 2026-11-09

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-62851; retrieved 2026-11-10; source updated 2026-11-09

- GitHub Security Advisories: https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-wqq7-4q7m-273v; retrieved 2026-11-08; source updated 2026-07-15

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-62851; retrieved 2026-11-09; source updated Not reported

Revision: 9fdb2721dc3a0fa0ad975b2096d36e358a53a2ec3d2b5347ff70b7f1bb9091ac

Canonical: https://y2.dev/cve/CVE-2026-62851

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

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