CVE-2026-39857 PUBLISHED

Information Disclosure via `choices`/`counts` Query Parameters Bypassing publicApiProjection Field Restrictions

Assigner: GitHub_M
Reserved: 07.04.2026 Published: 15.04.2026 Updated: 16.04.2026

ApostropheCMS is an open-source Node.js content management system. Versions 4.28.0 and prior contain an authorization bypass vulnerability in the choices and counts query parameters of the REST API, where these query builders execute MongoDB distinct() operations that bypass the publicApiProjection restrictions intended to limit which fields are exposed publicly. The choices and counts parameters are processed via applyBuildersSafely before the projection is applied, and MongoDB's distinct operation does not respect projections, returning all distinct values directly. The results are returned in the API response without any filtering against publicApiProjection or removeForbiddenFields. An unauthenticated attacker can extract all distinct field values for any schema field type that has a registered query builder, including string, integer, float, select, boolean, date, slug, and relationship fields. Fields protected with viewPermission are similarly exposed, and the counts variant additionally reveals how many documents have each distinct value. Both the piece-type and page REST APIs are affected. This issue has been fixed in version 4.29.0.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS Score: 5.3

Product Status

Vendor apostrophecms
Product apostrophe
Versions
  • Version < 4.29.0 is affected

References

Problem Types

  • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor CWE