CVE-2026-12939 — Newsletters <= 4.15 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'link' Shortcode Attribute
The Newsletters Lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'link' attribute of the post_thumbnail (and newsletters_post_thumbnail) shortcodes…
Published: 2026-07-29 · CVSS: 6.4 · CVSS 3.1
The Newsletters Lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'link' attribute of the post_thumbnail (and newsletters_post_thumbnail) shortcodes in versions up to and including 4.15. This is due to insufficient input sanitization and output escaping in the post_thumbnail() method in helpers/shortcode.php, which concatenates the user-controlled $link shortcode attribute directly into an href attribute without esc_url() or esc_attr(). 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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7