Cyber Resilience

CVE-2026-54390

Public PoC
Published
18 June 2026
Modified
23 June 2026
CVSS Score v4 9.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0060 47th percentile
Risk Priority 46 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-54390 is a critical-severity Improper Neutralization of Special Elements Used in a Template Engine (CWE-1336) vulnerability. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Template Injection (T1221); ranked at the 47th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-1336

Related Threats

MITRE ATT&CK Enterprise Techniques

T1221 Template Injection Stealth
Adversaries may create or modify references in user document templates to conceal malicious code or force authentication attempts.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-49136Shared CWE-1336
CVE-2025-68929Shared CWE-1336
CVE-2025-26865Shared CWE-1336
CVE-2024-27623Shared CWE-1336
CVE-2026-82447Shared CWE-1336
CVE-2026-12894Shared CWE-1336
CVE-2025-10380Shared CWE-1336
CVE-2026-72716Shared CWE-1336
CVE-2026-75574Shared CWE-1336
CVE-2025-27516Shared CWE-1336

Affected Assets

—
JTL Shop
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.3.2
  • V1.3.7
  • V1.3.10

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and static analysis can discover missing neutralization of template directives.

SI-10 Information Input Validation good match

Input validation rejects or sanitizes untrusted data before it reaches the template engine, stopping injection of special syntax.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles require use of safe templating APIs and proper escaping of external input.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
prevents

Secure SDLC practices directly require proper input neutralization in template engines to prevent injection.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and sanitization that directly prevents template-injection weaknesses.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for neutralizing special elements in template engines.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles reduce the likelihood of unsafe template processing but do not prescribe specific neutralization techniques.

A.8.28 Secure coding partial match
prevents

Secure coding standards require proper escaping or sandboxing of template directives, directly mitigating CWE-1336.

A.8.29 Security testing in development and acceptance partial match
finds

Security testing can detect template-injection flaws but does not itself implement neutralization controls.

References