CVE-2026-42051
Medium
Description
Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, the system API endpoint leaks license data and installed version to authenticated users. This issue has been patched in versions 4.9.0 and 5.4.0.
SeverityMedium
CVSS4.3
Exploit probability—
Product
Kirby
PublishedMay 9, 2026
First seenMay 9, 2026
Weakness typeCWE-862Missing authorization
How to fix
Update
- getkirby kirby4.9.0, 5.4.0 or later
- getkirby/cms4.9.0, 5.4.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| getkirby kirby | v < 4.9.0, 5.0.0 ≤ v < 5.4.0 | 4.9.0, 5.4.0 |
| getkirby/cmsPackagist | v < 4.9.0, 5.0.0 ≤ v < 5.4.0 | 4.9.0, 5.4.0 |
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