Kirby CMS's system API endpoint leaks installed version and license data to authenticated users — CVE-2026-42051

Summary

### TL;DR This vulnerability affects all Kirby sites that might have potential attackers in the group of authenticated Panel users. ---- ### Introduction Missing authorization allows authenticated users to perform actions they are not intended to have access to. The effects of missing authorization can include unauthorized access to sensitive information as well as unauthorized changes to content or system…

Product

composer: getkirby/cms

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Related advisories