CVE-2026-71553: Apostrophecms Apostrophe

High severity, CVSS 7.1. EPSS: 0.4% chance of exploitation in the next 30 days.

ApostropheCMS is an open-source Node.js content management system. In 4.32.0 and earlier, PATCH /api/v1/article/:id accepts the inherited path toString.call and passes it through the utility module to apos.util.set() and apos.util.get(), allowing an authenticated editor to overwrite the shared Object.prototype.toString function's call property and cause a persistent process-wide denial of service until restart.

Affected products

• Apostrophecms Apostrophe: up to and including 4.32.0

Published 2026-08-17. Last modified 2026-09-09.