A vulnerability categorized as critical has been discovered in JTL Shop up to 5.1.7/5.5.3/5.6.1/5.7.1 . This vulnerability affects unknown code of the component Encryption Key Handler . Such manipulation leads to improper neutralization of special elements used in a template engine. This vulnerability is traded as CVE-2026-54390 . The attack may be launched remotely. There is no exploit available. It is advisable to upgrade the affected component.