CVE-2021-34254: Umbraco CMS

Medium severity, CVSS 6.1. EPSS: 0.7% chance of exploitation in the next 30 days.

Umbraco CMS before 7.15.7 is vulnerable to Open Redirection due to insufficient url sanitization on booting.aspx.

Affected products

• Umbraco Umbraco CMS: before 7.15.7 (fixed in 7.15.7)

Published 2021-06-28. Last modified 2026-06-17.