Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Apostrophecms | Apostrophecms | < 4.29.0 |
Related Weaknesses (CWE)
References
- https://github.com/apostrophecms/apostrophe/commit/6c2b548dec2e3f7a82e8e16736603Patch
- https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-c276-fj82-fExploitMitigationVendor Advisory
- https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-c276-fj82-fExploitMitigationVendor Advisory
FAQ
What is CVE-2026-39857?
CVE-2026-39857 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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, w...
How severe is CVE-2026-39857?
CVE-2026-39857 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-39857?
Check the references section above for vendor advisories and patch information. Affected products include: Apostrophecms Apostrophecms.