CVE-2024-6639: MDx <= 2.0.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via mdx_list_item Shortcode

Severity: medium (CVSS 6.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-08-12 · updated 2026-06-17
Weakness: CWE-79

Description

The MDx theme for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'mdx_list_item' shortcode in all versions up to, and including, 2.0.3 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Affected products

AxtonYao MDx: through 2.0.3

References

https://github.com/yrccondor/mdx
https://github.com/yrccondor/mdx/commit/0906438824b8fab72715e7d5aec348aef0792721
https://www.wordfence.com/threat-intel/vulnerabilities/id/23ae17a6-a745-42c4-8627-ad1c41b66e0e?source=cve

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