CVE-2026-31857: Craft CMS

High severity, CVSS 8.8. EPSS: 0.9% chance of exploitation in the next 30 days.

Craft is a content management system (CMS). Prior to 5.9.9 and 4.17.4, a Remote Code Execution vulnerability exists in the Craft CMS 5 conditions system. The BaseElementSelectConditionRule::getElementIds() method passes user-controlled string input through renderObjectTemplate() -- an unsandboxed Twig rendering function with escaping disabled. Any authenticated Control Panel user (including non-admin roles such as Author or Editor) can achieve full RCE by sending a crafted condition rule via standard element listing endpoints. This vulnerability requires no admin privileges, no special permissions beyond basic control panel access, and bypasses all production hardening settings (allowAdminChanges: false, devMode: false, enableTwigSandbox: true). Users should update to the patched 5.9.9 or 4.17.4 release to mitigate the issue.

Affected products

• Craft CMS Craft CMS: from 4.0.0.1, before 4.17.4 (fixed in 4.17.4); from 5.0.1, before 5.9.9 (fixed in 5.9.9); version 4.0.0 only; version 5.0.0 only

Published 2026-03-11. Last modified 2026-06-17.