CVE-2026-77871

medium

Description

The Post Snippets – Custom WordPress Code Snippets Customizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Shortcode Attributes in all versions up to, and including, 4.2.4 due to insufficient input sanitization and output escaping. 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. Entity-encoded payloads such as <script>...</script> survive WordPress's wp_kses_post on-save sanitization because kses does not decode HTML entities, and are only converted back into executable HTML tags at render time by the plugin's own shortcode filter. This requires snippet shortcodes to be enabled.

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/a46c37f4-245d-423f-bdad-296fdf377ecc?source=cve

https://plugins.trac.wordpress.org/changeset/3759640/post-snippets/trunk/src/PostSnippets/Shortcode.php

https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L70

https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L29

https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L183

https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L140

https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L70

https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L29

https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L183

https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L140

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-111606

Details

Source: Mitre, NVD

Published: 2026-10-28

Updated: 2026-10-28

Risk Information

CVSS v2

Base Score: 5.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 6.4

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Severity: Medium

EPSS

EPSS: 0.00241