CVE-2026-33159: Craft CMS

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Craft CMS is a content management system (CMS). From version 4.0.0-RC1 to before version 4.17.8 and from version 5.0.0-RC1 to before version 5.9.14, guest users can access Config Sync updater index, obtain signed data, and execute state-changing Config Sync actions (regenerate-yaml, apply-yaml-changes) without authentication. This issue has been patched in versions 4.17.8 and 5.9.14.

Affected products

• Craft CMS Craft CMS: after 4.0.0, before 4.17.8 (fixed in 4.17.8); after 5.0.0, before 5.9.14 (fixed in 5.9.14); version 4.0.0 only; version 5.0.0 only

Published 2026-03-24. Last modified 2026-06-17.