CVE-2026-6403

High

Published: 15 May 2026

Published

15 May 2026

Modified

15 May 2026

KEV Added

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Patch

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CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Score 0.0035 58.1th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-6403 is a high-severity Path Traversal (CWE-22) vulnerability in Wordpress (inferred from references). Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 41.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-30517

Vulnerability details

The Quick Playground plugin for WordPress is vulnerable to Path Traversal in versions up to and including 1.3.3. This is due to insufficient path validation in the qckply_zip_theme() function, which appends a user-controlled 'stylesheet' parameter directly to the theme root…

directory path without sanitizing directory traversal sequences. This makes it possible for unauthenticated attackers to trigger the creation of a ZIP archive containing arbitrary files from the server's filesystem — including wp-config.

CWE(s): CWE-22

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1005 Data from Local System Collection

Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.

attack.mitre.org →

Why these techniques?

Path traversal in public-facing WordPress plugin enables unauthenticated file read (wp-config and others) via crafted requests.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1