kirby-modules License Key Disclosure via modules/activate Dialog

Summary

kirby-modules through 5.5.7, fixed in commit 315417e, contains an information disclosure vulnerability that allows any authenticated Kirby Panel user to retrieve the full plaintext commercial license key by sending a GET request to the modules/activate dialog endpoint. The plugin's activate dialog handler in lib/areas.php returns the complete key via ModulesLicense::readKey() without performing an administrator check, as the dialog is gated only by the access.system permission which defaults to true for all non-admin roles, enabling attackers to use the disclosed key to activate the plugin on arbitrary third-party installations.