LazyLoad Plugin <= 2.4.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via YouTube Video Title
- ID
- WPSEC-2026-0539
- Plugin
- LazyLoad Plugin – Lazy Load Images, Videos, and Iframes (rocket-lazy-load)
- Affected
- from 2.3.8.2 before 2.4.1
- Remediation
- Update to 2.4.1 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N
- Weakness
- CWE-79
- Usage
- Plugin Medium · Affected versions Medium among sites WPSec scans, 2026-10-07
- Attack surface
- LazyLoad Plugin on WPSec AttackSurface
- Fix released
- Published
Description
The LazyLoad Plugin plugin for WordPress is vulnerable to DOM-based Stored Cross-Site Scripting via the title of embedded YouTube videos in versions 2.3.8.2 up to, and including, 2.4.0. This is due to the front-end YouTube preview script inserting the video iframe's title, read back from the data-alt attribute, into markup through innerHTML without escaping. 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, by embedding a YouTube video whose title they control. Exploitation requires the 'Iframes & Videos' and 'Replace Youtube videos by thumbnail' options to be enabled.
References
- https://wpsec.com/vuln/WPSEC-2026-0539/
- https://plugins.svn.wordpress.org/rocket-lazy-load/tags/2.4.1/
- https://wordpress.org/plugins/rocket-lazy-load/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
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