a3 Lazy Load <= 2.7.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Video Element

Wordfence Intelligence > Vulnerability Database > a3 Lazy Load <= 2.7.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Video Element

6.4

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

CVE	CVE-2026-6427
CVSS	6.4 (Medium)
Publicly Published	May 27, 2026
Last Updated	May 28, 2026
Researcher	theviper17y

Description

The a3 Lazy Load plugin for WordPress is vulnerable to Stored Cross-Site Scripting in all versions up to, and including, 2.7.6 This is due to a regex bug in the _filter_videos() method that breaks HTML attribute quoting when processing crafted <video> elements, combined with unescaped output in the admin/views/form-data.php template. An authenticated attacker with Contributor-level access can insert a crafted <video> tag whose src attribute contains an embedded class=" substring that tricks the plugin's class-replacement regex into consuming an attribute-value closing quote. This shifts the HTML5 parser's quote boundary, promoting attacker-controlled text from inside a quoted attribute value into standalone event-handler attributes (autofocus, onfocus). The injected script executes in the browser of any user (including administrators) who views the post.

Learn more about Cross-Site Scripting vulnerabilities and how to prevent them.

References

Vulnerability Details for a3 Lazy Load

a3 Lazy Load

Software Type	Plugin
Software Slug	a3-lazy-load (view on wordpress.org)
Patched?	Yes
Remediation	Update to version 2.7.7, or a newer patched version
Affected Version	<= 2.7.6
Patched Version	2.7.7

Recent vulnerabilities in a3 Lazy Load

a3 Lazy Load <= 2.7.5 - Authenticated (Contributor+) Stored Cross-Site Scripting

6.4

CVE-2025-9873

Dec 12, 2025

Researcher: stealthcopter

a3 Lazy Load <= 2.6.0 - Cross-Site Request Forgery to Settings Reset

8.8

CVE ID Unknown

Nov 2, 2022

Researchers:

a3rev Multiple Plugins <= Various Versions - Cross-Site Request Forgery to Settings Changes

8.8

CVE ID Unknown

May 24, 2022

Researchers:

#	Title	CVE ID	CVSS	Researchers	Date
1	a3 Lazy Load <= 2.7.5 - Authenticated (Contributor+) Stored Cross-Site Scripting	CVE-2025-9873	6.4	stealthcopter	December 12, 2025
2	a3 Lazy Load <= 2.6.0 - Cross-Site Request Forgery to Settings Reset		8.8		November 2, 2022
3	a3rev Multiple Plugins <= Various Versions - Cross-Site Request Forgery to Settings Changes		8.8		May 24, 2022

View more vulnerabilities in this software package View more vulnerabilities

This record contains material that is subject to copyright.

License: Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy. Read more.

License: CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy. Read more.

Have information to add, or spot any errors? Contact us at wfi-support@wordfence.com so we can make any appropriate adjustments.

Did you know Wordfence Intelligence provides free personal and commercial API access to our comprehensive WordPress vulnerability database, along with a free webhook integration to stay on top of the latest vulnerabilities added and updated in the database? Get started today!

Learn more

Want to get notified of the latest vulnerabilities that may affect your WordPress site?
Install Wordfence on your site today to get notified immediately if your site is affected by a vulnerability that has been added to our database.

Get Wordfence

The Wordfence Intelligence WordPress vulnerability database is completely free to access and query via API. Please review the documentation on how to access and consume the vulnerability data via API.

Documentation