CVE-2026-50279: Craft CMS CMS

High severity, CVSS 7.6. EPSS: 0.4% chance of exploitation in the next 30 days.

Craft CMS is a content management system (CMS). IN versions 5.0.0-RC1 and above prior to 5.9.21, theEntriesController::actionSaveEntry() performs entry-edit permission checks before request-controlled author changes are applied to the model, allowing for authorship spoofing. The subsequent author mutation path accepts attacker-supplied authors / author parameters and allows the change when the current user is one of the old authors. Because the controller does not re-run authorization after mutating the author list, a low-privileged user can reassign an entry’s authorship to another user without holding the dedicated peer-author-change permission. This issue has been fixed in version 5.9.21.

Affected products

• Craft CMS CMS: from 5.0.0-RC1, before 5.9.21 (fixed in 5.9.21)

Published 2026-07-02. Last modified 2026-07-02.