ShellCodeX
Tools • Events • News • Insights
ShellCodeX vulnerability brief
MEDIUM Received

CVE-2026-12939

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.

Published 29 Jul 2026, 02:16 UTC Last modified 29 Jul 2026, 16:17 UTC
01

Attack profile

The conditions required to exploit this vulnerability and its potential impact.

Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Scope Changed
Confidentiality Low
Integrity Low
Availability None
Exploitability3.1
Impact2.7
02

Affected products

Product applicability statements supplied with the NVD record.

NVD has not published structured affected-product data for this record.
03

Weakness classification

CWE categories help security teams group the underlying software weakness.

04

Source references

External advisories, patches and technical reports attached to this CVE record.