GHSA-265m-7826-wjqm: Craft CMS: Authenticated RCE via `condition.config` JSON cleanse bypass

Craft CMS has an authenticated remote code execution issue in the control panel element-search condition handling.

Craft cleans the outer request-controlled condition array with Component::cleanseConfig(), but Conditions::createCondition() later decodes and merges the JSON string in condition.config without re-running cleanseConfig() on the decoded/merged configuration.

Because condition.config is a JSON string during the first cleanse, Yii special config keys such as as … and on … can be hidden inside it. After JSON decoding, those keys reach FieldLayout object creation and are interpreted by Yii as behavior/event configuration.

The RCE is semi-blind: the trigger endpoint returns a normal JSON response, and the command output is verified via a server-side file-write side effect retrieved in a subsequent request.