AlchemyCMS: Unauthenticated nested page API leaks restricted & unpublished content

Exploitation

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

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Unauthenticated nested page API leaks restricted & unpublished content - Location: app/controllers/alchemy/api/pagescontroller.rb:28 (Api::PagesController#nested) - Affected version: Alchemy CMS 8.3.0.dev (Rails 8.1.3) Description The unauthenticated GET /api/pages/nested endpoint returns the full page tree to any anonymous caller, including restricted (member-only) pages and unpublished/draft pages that should be hidden. Appending ?elements=true additionally dumps the element/ingredient content of restricted pages, fully bypassing the access control the sibling show and index actions enforce. Root cause Api::PagesController#nested calls no authorize! and applies no published/restricted scoping, unlike show (authorize! :show) and index (accessibleby(currentability, :index)). PageTreePreloader loads page.selfanddescendants unfiltered, and PageTreeSerializer emits every page's metadata (and, with elements, publicversion.elements) with no ability check. Evidence An unauthenticated GET…

Published by the source

19 Jun 2026, 17:47 UTC

Last modified by the source

19 Jun 2026, 17:47 UTC

Source last checked

26 Oct 2026, 15:52 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-mqq5-j7w8-2hgh

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# Patch Next advisory brief: GHSA-mqq5-j7w8-2hgh

Advisory: AlchemyCMS: Unauthenticated nested page API leaks restricted & unpublished content
IDs: GHSA-mqq5-j7w8-2hgh
Record: https://patchnext.com/advisories/ghsa-mqq5-j7w8-2hgh (revision 1, source checked 26 Oct 2026, 15:52 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: alchemy_cms 8.2.6, 8.1.14, 8.0.15, 7.4.15. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems alchemy_cms: affected >= 8.2.0, <= 8.2.5; >= 8.1.0, <= 8.1.13; >= 8.0.0.a, <= 8.0.14; <= 7.4.14; fixed in 7.4.15, 8.0.15, 8.1.14, 8.2.6

## Suggested inspection (read-only)
- RubyGems alchemy_cms: 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 alchemy_cms.
- 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-mqq5-j7w8-2hgh (GitHub-reviewed advisory GHSA-mqq5-j7w8-2hgh lists affected ranges: RubyGems alchemy_cms >=8.2.0 =8.1.0 =8.0.0.a =0 <=7.4.14)

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