CVE-2026-77871

Post Snippets <= 4.2.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

Published Oct 28, 2026 CVSS 3.1 · 6.4 Medium EPSS < 1% KEV · Not listed
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 &lt;script&gt;...&lt;/script&gt; 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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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 &lt;script&gt;...&lt;/script&gt; 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.
Title Post Snippets <= 4.2.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
Wordfence
Published
Updated
Oct 29, 2026, 1:41 AM
Reserved
Aug 21, 2026, 2:55 PM
Status
Deferred
Published
Oct 28, 2026, 7:16 AM
Modified
Oct 29, 2026, 2:16 AM