Auth bypass in Craftcms Cms

CVE-2026-33159

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.

Vulnerability class: Broken Authentication

EPSS: 0.003 (23.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33159?
CVE-2026-33159 is a medium-severity vulnerability in Craftcms Cms, classified under Missing Authentication for Critical Function. CVSS score: 6.5/10. Published 2026-03-24.
How severe is CVE-2026-33159?
Medium severity. CVSS v3 base score is 6.5 out of 10.