CVE Catalog

CVE-2026-77871

MediumCVSS 6.4
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.24%

15th percentile - higher than 15% of all known CVEs

Summary

The Post Snippets plugin for WordPress in versions up to and including 4.2.4 is vulnerable to stored cross-site scripting (XSS) via shortcode attributes due to insufficient input sanitization and output escaping. Authenticated attackers with contributor-level access can inject arbitrary web scripts that execute when a user visits an injected page, provided snippet shortcodes are enabled.

Risk Assessment

An attacker could execute arbitrary JavaScript in a user's browser, potentially leading to account takeover or other attacks. However, this requires content creation privileges and enabled shortcodes.

Recommendation

Update the Post Snippets plugin to a version later than 4.2.4. Additionally, consider restricting contributor permissions and implementing a Content Security Policy (CSP).

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS