a3 Lazy Load <= 2.7.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Video Element
Summary
| CVE | CVE-2026-6427 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-28 08:16:36 UTC |
| Updated | 2026-05-28 13:45:25 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 6.4 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
EPSS: 0.000420000 probability, percentile 0.132380000 (date 2026-06-01)
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 6.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 6.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
ChangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | A3rev | A3 Lazy Load | affected 2.7.6 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/admin/views/form-data.php | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/5246efbb-93cc-4951-900e-d13d0... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Youcef Hamdani (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-05-27T18:25:51.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.