CVE-2026-18344 Responsive Thumbnail Slider < 1.1.53 - Reflected Cross-Site Scripting via 'id' Parameter
Unauthenticated attackers can inject arbitrary scripts via the 'id' parameter, potentially executing code in victim browsers if they click a crafted link.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-18344?
CVE-2026-18344 is a medium-severity cross-site scripting vulnerability in nik00726 Responsive Thumbnail Slider, published on 1 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-18344?
How do I fix CVE-2026-18344?
No fix has been published for CVE-2026-18344 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-18344 being exploited?
There is no known exploitation of CVE-2026-18344 in the wild and no public exploit code.
Sources
Also known as GHSA-j3m7-4pfh-6m64.