{"id":"CVE-2026-6427","state":"PUBLISHED","title":"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.","publishedAt":"2026-05-28T06:45:40.315Z","updatedAt":"2026-05-28T10:34:51.326Z","severity":{"score":6.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","source":"Wordfence"},"assigner":"Wordfence","products":["a3rev a3 Lazy Load"],"affected":[{"vendor":"a3rev","product":"a3 Lazy Load","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.7.6","versionType":"semver"}]}],"references":["https://www.wordfence.com/threat-intel/vulnerabilities/id/5246efbb-93cc-4951-900e-d13d08840f03?source=cve","https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L666","https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L643","https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L623","https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L136","https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L124","https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/admin/views/form-data.php#L11","https://plugins.trac.wordpress.org/changeset?old_path=%2Fa3-lazy-load/tags/2.7.6&new_path=%2Fa3-lazy-load/tags/2.7.7"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/6xxx/CVE-2026-6427.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-6427","state":"PUBLISHED","datePublished":"2026-05-28T06:45:40.315Z","dateUpdated":"2026-05-28T10:34:51.326Z","assignerShortName":"Wordfence","assignerOrgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateReserved":"2026-04-16T12:17:02.076Z"},"containers":{"cna":{"title":"a3 Lazy Load <= 2.7.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Video Element","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"a3rev","product":"a3 Lazy Load","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"2.7.6","versionType":"semver"}]}],"references":[{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/5246efbb-93cc-4951-900e-d13d08840f03?source=cve"},{"url":"https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L666"},{"url":"https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L643"},{"url":"https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L623"},{"url":"https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L136"},{"url":"https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/classes/class-a3-lazy-load.php#L124"},{"url":"https://plugins.trac.wordpress.org/browser/a3-lazy-load/trunk/admin/views/form-data.php#L11"},{"url":"https://plugins.trac.wordpress.org/changeset?old_path=%2Fa3-lazy-load/tags/2.7.6&new_path=%2Fa3-lazy-load/tags/2.7.7"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","baseScore":6.4,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"Wordfence","orgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateUpdated":"2026-05-28T06:45:40.315Z"},"credits":[{"lang":"en","type":"finder","value":"Youcef Hamdani"}],"timeline":[{"time":"2026-05-27T18:25:51.000Z","lang":"en","value":"Disclosed"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-28T10:27:27.438644Z","id":"CVE-2026-6427","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-28T10:34:51.326Z"}}]}}}