Vulnerability Database

383,304

Total vulnerabilities in the database

AlchemyCMS: Unauthenticated nested page API leaks restricted & unpublished content — alchemy_cms

Missing Authorization

Unauthenticated nested page API leaks restricted & unpublished content

  • Location: app/controllers/alchemy/api/pages_controller.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endpoint returns the full page tree to any anonymous caller, including restricted (member-only) pages and unpublished/draft pages that should be hidden.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 (accessible_by(current_ability, :index)). PageTreePreloader loads page.self_and_descendants unfiltered, and PageTreeSerializer emits every page's metadata (and, with elements, public_version.elements) with no ability check.

Evidence

An unauthenticated GET /api/pages/nested returns HTTP 200 with the restricted page ("restricted":true) and an unpublished draft ("public":false); ?elements=true leaks its content (e.g. TOPSECRET_RESTRICTED_BODY_proof123). The same guest hitting GET /api/pages/3 (show) gets HTTP 403 {"error":"Not authorized"}, proving nested returns what show correctly denies.

Reproduction

# 1) Metadata leak (guest, no auth) curl -s http://localhost:3000/api/pages/nested | python3 -m json.tool | grep -E '"name"|"restricted"|"public"' # 2) Content leak of restricted page curl -s "http://localhost:3000/api/pages/nested?elements=true" | grep -oE 'TOPSECRET_RESTRICTED_BODY_[A-Za-z0-9]+|RESTRICTED_RICHTEXT_[A-Za-z0-9]+' # 3) Contrast — show denies the same guest curl -s -o /dev/null -w "show /api/pages/3 -> HTTP %{http_code}\n" http://localhost:3000/api/pages/3

Suggested fix

def nested @page = Page.find_by(id: params[:page_id]) || Language.current_root_page authorize! :show, @page preloaded_page = PageTreePreloader.new(page: @page, user: current_alchemy_user, ability: current_ability).call render json: PageTreeSerializer.new(preloaded_page, ability: current_ability, user: current_alchemy_user, elements: params[:elements]) end

Additionally scope PageTreePreloader's self_and_descendants via accessible_by(current_ability) and gate element emission in PageTreeSerializer#page_elements behind opts[:ability].can?(:show, page).

  • Published: Jun 19, 2026
  • Updated: Jun 20, 2026
  • GHSA: GHSA-mqq5-j7w8-2hgh
  • Severity: High
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: High
  • Score: 7.5
  • AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CWEs:

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