CVE-2026-86732

Craft CMS versions before 5.10.12 contain a remote code execution vulnerability in the element-index endpoint that allows authenticated content editors to instantiate arbitrary classes through the criteria parameter. Attackers can inject a malicious class via criteria[withTransforms][0][class] that reaches ImageTransforms::normalizeTransform(), then use a PHP gadget chain with yii\rbac\PhpManager to execute code by pointing itemFile to a request log containing PHP payload in the User-Agent header.

• https://github.com/craftcms/cms/security/advisories/GHSA-9wcj-wqqh-cqvg
• https://www.vulncheck.com/advisories/craft-cms-before-5.10.12-remote-code-execution-via-element-index