CVE-2026-54390 | JTL Shop versions 5.2.0 through 5.7.1 contains a server-side… | CVSS 9.8 CRITICAL

Description

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.

Metadata

CVE ID: CVE-2026-54390
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-12 20:20 UTC
Published: 2026-06-18 17:33 UTC
Last updated: 2026-06-18 17:33 UTC
Primary CWE: CWE-1336
Improper Neutralization of Special Elements Used in a Templa…
Vendor / Product: JTL Software / JTL Shop
Sources: cve.org · NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products (1)

Vendor	Product	Platform	Versions
JTL Software	JTL Shop	—	5.0.0 ≤ 5.1.8, 5.2.0 ≤ 5.3.x, 5.4.0 ≤ 5.7.1, 5.5.4 …

Weakness (CWE)

CWE	Source	Description
CWE-1336	cna	Improper Neutralization of Special Elements Used in a Template Engine

CVSS scores (2)

Score	Severity	Version	Source	Vector
9.8	CRITICAL	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3	CRITICAL	4.0	cna	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References (3)