Server-Side Template Injection in JTL Shop Smarty Engine
CVE-2026-54390 is a critical server-side template injection (SSTI) vulnerability in JTL Shop versions 5.2.0 through 5.7.1. The flaw is caused by unsanitized user-supplied input being passed to the Smarty template engine, allowing unauthenticated remote attackers to inject and evaluate malicious template syntax on the server. Successful exploitation can disclose sensitive server-side data, including database credentials and encryption keys. In JTL Shop versions 5.4.0 through 5.7.1, the impact is more severe because attackers can abuse registered Smarty modifiers, including unserialize and file_get_contents, to write a webshell into the web root and achieve arbitrary command execution as the web server user.
Are you exposed to this one?
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
5 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.