# CVE-2026-39857: ApostropheCMS information disclosure via choices and counts query parameters

Source: https://junglewise.ai/threats/cve-2026-39857-apostrophecms-information-disclosure-via-choices-and-counts-query  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-15. Updated: 2026-05-11  
License: CC BY 4.0 with a link back

CVE-2026-39857 · Severity: medium · CVSS 5.3 · Published 2026-04-15

ApostropheCMS is a content management system used to build and manage websites. A vulnerability in its web interface allows unauthenticated visitors to bypass security restrictions and view sensitive data fields that were intended to be hidden. This could lead to the exposure of internal status values, categories, or other restricted information stored within the system.

Technologies: [ApostropheCMS](https://junglewise.ai/threats/technologies/apostrophecms), [apostrophe (npm)](https://junglewise.ai/threats/technologies/apostrophe). Vendors: [ApostropheCMS](https://junglewise.ai/threats/vendors/apostrophecms), [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-39857 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-39857 being exploited in the wild.

**How severe is CVE-2026-39857?** Medium severity, with a CVSS score of 5.3, published 15 April 2026.

**Which products and versions are affected?** ApostropheCMS <= 4.28.0; apostrophe (npm) <= 4.28.0, SEMVER:introduced=0,fixed=4.29.0.

**Is there a fix for CVE-2026-39857?** Yes. apostrophe (npm): upgrade to 4.29.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-39857 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-39857?** Check whether you run ApostropheCMS or apostrophe (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- apostrophe (npm): upgrade to 4.29.0 or later

  ```sh
  npm install apostrophe@4.29.0
  ```


## Technical details

An information disclosure vulnerability exists in ApostropheCMS due to the way the REST API handles 'choices' and 'counts' query parameters. While the main API query enforces field restrictions via 'publicApiProjection' using MongoDB projections, the 'choices' and 'counts' builders use a separate code path that utilizes the MongoDB 'distinct' operation. Because 'distinct' does not respect projections, unauthenticated attackers can extract all unique values and document counts for any schema field, including those explicitly excluded from public view or protected by 'viewPermission'. This affects both the piece-type and page REST APIs. The issue is fixed in version 4.29.0.

## Affected products

- ApostropheCMS apostrophe <= 4.28.0

## Identifiers

- CVE-2026-39857
- GHSA-c276-fj82-f2pq

## Timeline

- 2026-04-15: patched: Fixed in version 4.29.0
- 2026-04-15: disclosed
- 2026-04-16: advisory

## References

- [https://api.github.com/users/offset](https://api.github.com/users/offset)
- [https://github.com/offset](https://github.com/offset)
- [https://api.github.com/users/offset/gists%7B/gist_id%7D](https://api.github.com/users/offset/gists%7B/gist_id%7D)
- [https://api.github.com/users/offset/repos](https://api.github.com/users/offset/repos)
- [https://avatars.githubusercontent.com/u/114768995?v=4](https://avatars.githubusercontent.com/u/114768995?v=4)
- [https://api.github.com/users/offset/events%7B/privacy%7D](https://api.github.com/users/offset/events%7B/privacy%7D)

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- [ApostropheCMS unauthenticated file upload in import routes](https://junglewise.ai/threats/cve-2026-113711-apostrophecms-is-an-open-source-node-js-content-management)
- [ApostropheCMS password-change endpoint lacks attempt throttling](https://junglewise.ai/threats/cve-2026-113710-apostrophecms-no-attempt-throttling-on-authenticated-password)
- [ApostropheCMS page REST API authorization bypass](https://junglewise.ai/threats/cve-2026-113670-apostrophecms-page-rest-api-authorization-bypass)
- [ApostropheCMS cross-domain session token in URL confers session takeover](https://junglewise.ai/threats/cve-2026-113669-apostrophecms-cross-domain-session-token-in-url-confers-session)
- [ApostropheCMS REST route authorization bypass in locales endpoint](https://junglewise.ai/threats/cve-2026-113668-apostrophecms-id-locales-rest-route-omits-the-public-api)