CVE-2026-31857
Description
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.
How to fix
- craftcms craft_cms4.17.4, 5.9.9 or later
- craftcms/cms5.9.9, 4.17.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| craftcms craft_cms | 4.0.0.1 ≤ v < 4.17.4, 5.0.1 ≤ v < 5.9.9, 4.0.0, 5.0.0 | 4.17.4, 5.9.9 |
| craftcms/cmsPackagist | 5.0.0-RC1 ≤ v < 5.9.9, 4.0.0-beta.1 ≤ v < 4.17.4 | 5.9.9, 4.17.4 |
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