CVE-2026-53609

Received
Published: 12 Jun 2026, 20:59
Last modified:12 Jun 2026, 20:59

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.1 CRITICAL
v3.1 (cve.org)
EPSS Score
0.05% LOW
0% probability
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

12 Jun 2026, 20:59
Published
Vulnerability first disclosed

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.

CVSS Metrics

  • v3.1•CRITICAL•Score: 9.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L

EPSS Trends

Current EPSS score: 0.05%• Percentile: 17%

Techniques & Countermeasures

  • CWE-1321•Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

    The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

Affected Systems

  • apostrophecms•apostrophe

    ≤ 4.30.0

References (1)