CVE-2026-6403 | Quick Playground <= 1.3.3 - Unauthenticated Path Traversal to Arbitrary File Read via 'stylesheet' Parameter

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.

Published: 2026-05-15 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-6403 is rated Moderate Risk (48.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.81%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-6403

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.35% 0.81% +0.46%
2 2026-05-21 0.27% 0.35% +0.08%
3 2026-05-15 0.27%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-6403

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-6403

GitHub Security Advisory for CVE-2026-6403

GHSA-5vxp-83xg-5c9f · Severity: high — The Quick Playground plugin for WordPress is vulnerable to Path Traversal in versions up to and...

Affected software / configurations for CVE-2026-6403

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-6403

URL Tags
https://plugins.trac.wordpress.org/browser/quick-playground/tags/1.3.1/api.php#L62
https://plugins.trac.wordpress.org/browser/quick-playground/tags/1.3.1/api.php#L631
https://plugins.trac.wordpress.org/browser/quick-playground/tags/1.3.1/utility.php#L162
https://plugins.trac.wordpress.org/browser/quick-playground/tags/1.3.1/utility.php#L248
https://plugins.trac.wordpress.org/browser/quick-playground/trunk/api.php#L62
https://plugins.trac.wordpress.org/browser/quick-playground/trunk/api.php#L631
https://plugins.trac.wordpress.org/browser/quick-playground/trunk/utility.php#L162
https://plugins.trac.wordpress.org/browser/quick-playground/trunk/utility.php#L248
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3514238%40quick-playground&new=3514238%40quick-playground&sfp_email=&sfph_mail=
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3523317%40quick-playground&new=3523317%40quick-playground&sfp_email=&sfph_mail=
https://www.wordfence.com/threat-intel/vulnerabilities/id/a39dccb6-b635-44af-b0e0-c3010b719773?source=cve
cvelogic Threat Intelligence