CVE-2026-53609

critical EU-CRITICAL

EUVD alias: EUVD-2026-36590

Published 2026-06-12 · Modified 2026-06-12

💬 Discuss on Community ✚ Propose mitigation

CVSS v3

9.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L

CVSS v4 NEW

—

not yet in upstream

VIR risk

9.1

Description

ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, `apos.util.set()` traverses dot-notation paths without sanitizing `__proto__`, allowing an authenticated editor to write arbitrary values to `Object.prototype` via the `$pullAll` patch operator. A confirmed gadget in `publicApiCheck()` causes this to bypass authorization on all piece-type REST API endpoints for every subsequent unauthenticated request, for the lifetime of the Node.js process. As of time of publication, no known patched versions are available.

Predictions

Exploit likelihood

94%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-6h5j-32cf-4253

CWEs

CWE-1321

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.