NetSight
critical9.1

CVE-2026-54003

Kirby: External Initialization of the Panel on reverse proxy setups with the `Forwarded` header

Impact

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.

Affected packages

EcosystemPackageAffectedFixed in
composergetkirby/cms<= 4.9.34.9.4

Weakness classification

References