# CVE-2026-54390: JTL Shop < 5.7.2 Server-Side Template Injection via Smarty Renderer

> Unauthenticated attackers can inject template syntax to read sensitive data or execute arbitrary commands via webshell upload in JTL Shop.

- **Severity:** Critical 9.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Jun 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-pxq6-fr5m-fwh5

## What is CVE-2026-54390?

CVE-2026-54390 is a critical code injection vulnerability in JTL Shop, published on 18 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-1336 (Improper Neutralization of Special Elements Used in a Template Engine)

## Which versions are affected by CVE-2026-54390?


## How do I fix CVE-2026-54390?

No fix has been published for CVE-2026-54390 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-54390 being exploited?

There is no known exploitation of CVE-2026-54390 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-54390 — JTL Shop Smarty SSTI RCE | Pre-Auth Template Injection via fetch('string:' . ) | 5.2.0-5.7.1 (github_poc): https://github.com/shinthink/CVE-2026-54390

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54390 and fix it if it is affected.

What it is: CVE-2026-54390 is a critical code injection vulnerability in JTL Shop, published on 18 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-54390 in the wild and no public exploit code.

Affected product: JTL Shop. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-54390/ (Markdown: https://insights.sbomify.com/CVE-2026-54390/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54390
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54390
- OSV: https://osv.dev/vulnerability/CVE-2026-54390

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54390/
Summaries are generated and may contain mistakes; the official description above is the record.