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Fencer Intel
medium 4.3

CVE-2026-62851 json

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

published 3mo ago modified 2d ago also EUVD-2026-118371 , GHSA-wqq7-4q7m-273v

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository freescout-help-desk/freescout. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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.

Patch / fix

  • freescout freescout 1.8.226

Is CVE-2026-62851 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2d ago

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected products

  • freescout-help-desk freescout

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-639 Authorization Bypass Through User-Controlled Key

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of freescout-help-desk/freescout published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.