ApostropheCMS: POST /api/v1/@apostrophecms/doc/slugTaken discloses existence of private/admin-only content to any authenticated user

Exploitation

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

CVSS

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

EPSS

• CVE-2026-112952: 0.33% estimated exploitation activity in the next 30 days; percentile 26.85 (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 The slugTaken endpoint returns a boolean indicating whether a slug is in use across all document types and visibility levels, with no permission or type filter. Any logged-in user (including editors) can enumerate the slug space of private pages, drafts, and archived content. Details POST /api/v1/@apostrophecms/doc/slugTaken with body { "slug": "target-slug" } runs a raw existence check against the documents collection. It does not: - Check whether the requesting user has read permission for documents of that type. - Filter by visibility (public, loginRequired, private). - Filter by viewRole. - Filter by publication status (draft vs published). A single authenticated session can iterate the slug space to enumerate the full content inventory of the CMS, including content the user is explicitly prohibited from viewing. PoC Impact Information disclosure. An attacker with any authenticated session can enumerate all slugs in the system, mapping the full content structure of the…

Published by the source

21 Oct 2026, 17:17 UTC

Last modified by the source

21 Oct 2026, 17:28 UTC

Source last checked

26 Oct 2026, 13:07 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-f66c-mpj2-3r8h

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-f66c-mpj2-3r8h

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-f66c-mpj2-3r8h

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# Patch Next advisory brief: CVE-2026-112952

Advisory: ApostropheCMS: POST /api/v1/@apostrophecms/doc/slugTaken discloses existence of private/admin-only content to any authenticated user
IDs: CVE-2026-112952, GHSA-f66c-mpj2-3r8h
Record: https://patchnext.com/advisories/cve-2026-112952 (revision 3, source checked 26 Oct 2026, 13:07 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: apostrophe 4.34.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm apostrophe: affected < 4.34.0; fixed in 4.34.0

## Suggested inspection (read-only)
- `npm ls apostrophe --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## 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 apostrophe.
- 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-f66c-mpj2-3r8h (GitHub-reviewed advisory GHSA-f66c-mpj2-3r8h lists affected ranges: npm apostrophe >=0 <4.34.0)
- Verified: https://osv.dev/vulnerability/GHSA-f66c-mpj2-3r8h (OSV record GHSA-f66c-mpj2-3r8h lists affected ranges: npm apostrophe >=0 <4.34.0 (fixed))

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