WordPress security changelog
MEDIUM CVE-2026-18344 Received

Responsive Thumbnail Slider reflects id into an HTML attribute

Responsive Thumbnail Slider before 1.1.53 echoes the unauthenticated id query parameter directly into a double-quoted attribute in responsive_thumbnail_image_management(). A numeric-prefix string passes the loose greater-than-zero check, while WordPress backslashes do not escape HTML, allowing a crafted link to execute JavaScript when a victim follows it.

CVE / CNA score 6.1 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Responsive Thumbnail Slider
Plugin slug
wp-responsive-thumbnail-slider
Affected
< 1.1.53
Safe version
1.1.53
Published
Aug 01, 2026
Weakness
CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Aug 01, 2026 and is one of 5 known issues for this plugin.

Update, patch or deactivate.

Update Responsive Thumbnail Slider to 1.1.53 or later. Review requests containing script-bearing id values and invalidate privileged sessions if an Administrator followed a confirmed link.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Technical description

The Wp Responsive Thumbnail Slider plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'id' parameter in versions up to, and excluding, 1.1.53. This is due to insufficient input sanitization and output escaping in the responsive_thumbnail_image_management() function, which echoes $_GET['id'] directly into a double-quoted HTML attribute with no esc_attr() call. The only guard is a loose PHP numeric comparison ($_GET['id']>0) that a string beginning with a numeric prefix trivially satisfies, and the addslashes() applied by wp_magic_quotes() is inert in HTML-attribute context because backslash is not an HTML escape character. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary and upstream sources