Craft Cms · Craft Cms · CVE-2026-33159
**Name of the Vulnerable Software and Affected Versions**
Craft CMS versions 4.0.0-RC1 through 4.17.7
Craft CMS versions 5.0.0-RC1 through 5.9.13
**Description**
Craft CMS is a content management system. Guest users can access the Config Sync updater `index`, obtain signed `data`, and execute state-changing Config Sync actions (`regenerate-yaml`, `apply-yaml-changes`) without authentication. The `ConfigSyncController` extends `BaseUpdaterController`, and the base updater is anonymously accessible for control panel requests. The `index` endpoint emits signed updater state (`data`), which can be reused by guests in subsequent requests. Sensitive actions reachable through this method include `actionApplyYamlChanges`, `actionRegenerateYaml`, `applyExternalChanges`, and `regenerateExternalConfig`. An attacker can send a POST request to `/admin/actions/config-sync/index` to extract the signed data, then reuse it in subsequent requests to endpoints like `/admin/actions/config-sync/regenerate-yaml` or `/admin/actions/config-sync/apply-yaml-changes`, potentially causing unauthorized configuration state transitions and a service integrity risk.
**Recommendations**
Craft CMS versions 4.0.0-RC1 through 4.17.7 should be updated to version 4.17.8 or later.
Craft CMS versions 5.0.0-RC1 through 5.9.13 should be updated to version 5.9.14 or later.