CVE-2026-53609CWE-1321

Apostrophe has Server-Side Prototype Pollution in apos.util.set via patch operators that leads to process-wide authorization bypass

Critical · published June 12, 2026

CVSS v3.1
9.1
EPSS
0%
Percentile
30.7
In the wild
Unconfirmed
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.

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L
CVSS v4.0
Not supplied
EPSS
0.00380 · 30.7th percentile
Weakness
CWE-1321 · Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Published
2026-06-12T20:59Z
EPSS history
Timeline
  • 12 JUN 20:59Z
    Apostrophe has Server-Side Prototype Pollution in apos.util.set via patch operators that leads to process-wide authorization bypass
    cvelistv5