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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
a3rev a3 Lazy Load unaffected
Version Status Constraints
0 affected ≤ 2.7.6

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Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/admin/views/form-data.php#L11 cve-icon
https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L124 cve-icon
https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L136 cve-icon
https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L623 cve-icon
https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L643 cve-icon
https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L666 cve-icon
https://plugins.trac.wordpress.org/changeset?old_path=%2Fa3-lazy-load/tags/2.7.6&new_path=%2Fa3-lazy-load/tags/2.7.7 cve-icon
https://www.wordfence.com/threat-intel/vulnerabilities/id/5246efbb-93cc-4951-900e-d13d08840f03?source=cve cve-icon
History

Thu, 28 May 2026 07:30:00 +0000

Type Values Removed Values 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.
Title a3 Lazy Load <= 2.7.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Video Element
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published:

Updated: 2026-05-28T06:45:40.315Z

Reserved: 2026-04-16T12:17:02.076Z

Link: CVE-2026-6427

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses