CVE-2026-6427
a3 Lazy Load <= 2.7.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Video Element
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.
INFO
Published Date :
May 28, 2026, 8:16 a.m.
Last Modified :
May 28, 2026, 8:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-6427
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the a3 Lazy Load plugin.
- Verify plugin configuration for safety.
- Remove any malicious content.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-6427.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-6427 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-6427
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-6427 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-6427 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
May. 28, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/admin/views/form-data.php#L11 Added Reference https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L124 Added Reference https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L136 Added Reference https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L623 Added Reference https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L643 Added Reference https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L666 Added Reference https://plugins.trac.wordpress.org/changeset?old_path=%2Fa3-lazy-load/tags/2.7.6&new_path=%2Fa3-lazy-load/tags/2.7.7 Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/5246efbb-93cc-4951-900e-d13d08840f03?source=cve