CVE-2026-54003
Critical
Description
Kirby is an open-source content management system. Prior to 4.9.4 and from 5.4.4, Kirby sites with no configured user accounts that run on publicly accessible servers behind a reverse proxy setting the Forwarded, X-Client-IP, or X-Real-IP request header could allow remote attackers to install the Panel and create the first admin user because local-IP checks trusted those headers incorrectly. This issue is fixed in versions 4.9.4 and 5.4.4.
SeverityCritical
CVSS9.1
Exploit probability—
ProductGetkirby/cms
PublishedJul 9, 2026
First seenJul 9, 2026
Weakness typeCWE-454CWE-454
How to fix
Update
- getkirby/cms4.9.4, 5.4.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| getkirby/cmsPackagist | v < 4.9.4, 5.0.0-alpha.1 ≤ v < 5.4.4 | 4.9.4, 5.4.4 |
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