CVE-2026-53609

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-12 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-25 23:10 UTC Last updatedMost recent change to the record

Details

Published

2026-06-12 22:16 UTC

Last modified

2026-10-25 23:10 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-1321 · Prototype pollution

Record status

Deferred

Attack profile CVSS 3.1 · 9.1

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

Low

Availability

Low