Description
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.
References6
- plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/h…
- plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/h…
- plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/h…
- plugins.trac.wordpress.org/browser/newsletters-lite/tags/4.15/i…
- plugins.trac.wordpress.org/changeset?reponame=&old=3621582%40ne…
- www.wordfence.com/threat-intel/vulnerabilities/id/2ca8ab94-45b8…
Metrics
- CVSS 3.1
-
6.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 29 · as of 13 November 2026
- CWE
- CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.