Froxlor has an authorization bypass in FTP shell assignment via missing server-side available_shells enforcement

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.6 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P · score source

EPSS

• CVE-2026-41235: 0.23% estimated exploitation activity in the next 30 days; percentile 13.60 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Froxlor 2.3.6 lets administrators configure system.availableshells as the approved shell list that customers may assign to FTP users. However, the server-side FTP account handlers do not enforce that whitelist when processing add or edit requests. As a result, an authenticated customer with shell delegation enabled can submit an arbitrary shell such as /bin/bash even when the panel UI only offers more restricted choices. In deployments that use the default nssextrausers integration, the attacker-controlled shell is then propagated into the system account database, leading to real host shell access. Details The customer-facing FTP account page builds the shell selector from system.availableshells, which shows that the product intends the setting to act as the authorization boundary: The request handler forwards posted form data directly into the FTP API command implementation: On the server side, Ftps::add() and Ftps::update() only perform generic shell string validation. They…

Published by the source

29 May 2026, 15:36 UTC

Last modified by the source

9 Jun 2026, 11:54 UTC

Source last checked

26 Oct 2026, 14:48 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-gcv3-5v9q-fmhh

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# Patch Next advisory brief: CVE-2026-41235

Advisory: Froxlor has an authorization bypass in FTP shell assignment via missing server-side `available_shells` enforcement
IDs: CVE-2026-41235, GHSA-gcv3-5v9q-fmhh
Record: https://patchnext.com/advisories/cve-2026-41235 (revision 1, source checked 26 Oct 2026, 14:48 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: froxlor/froxlor 2.3.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist froxlor/froxlor: affected >= 2.3.6, <= 2.3.6; fixed in 2.3.7

## Suggested inspection (read-only)
- Packagist froxlor/froxlor: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on froxlor/froxlor.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-gcv3-5v9q-fmhh (GitHub-reviewed advisory GHSA-gcv3-5v9q-fmhh lists affected ranges: Packagist froxlor/froxlor >=2.3.6 <=2.3.6)

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