CVE-2026-54390: Jtl Software Jtl Shop

Critical severity, CVSS 9.8. EPSS: 0.6% chance of exploitation in the next 30 days.

JTL Shop versions 5.2.0 through 5.7.1 contains a server-side template injection vulnerability that allows unauthenticated attackers to inject malicious template syntax due to unsanitized user-supplied input passed to the Smarty template engine. Attackers can exploit this flaw to read sensitive server-side values such as database credentials and encryption keys, and on versions 5.4.0 through 5.7.1, leverage registered Smarty modifiers including unserialize and file_get_contents to write a webshell to the web root and execute arbitrary commands as the web server user.

Affected products

• Jtl Software Jtl Shop: before 5.0.0 (fixed in 5.0.0); after 5.1.8

Published 2026-06-18. Last modified 2026-06-23.