CVE-2026-59727
Full vulnerability record from the local CVENow database.
Description
Astro is a web framework for content-driven websites. In versions 3.10.0 through 7.0.3, when a transition:persist, transition:scope, or transition:persist-props directive is applied to a client-hydrated (client:*) component, Astro copied the directive value onto the rendered <astro-island> element without HTML-escaping it. If a developer reflects attacker-controlled input into one of these directives, an attacker can break out of the attribute and inject arbitrary HTML/JavaScript into the server-rendered output, resulting in reflected cross-site scripting (XSS). Exploitation requires the application developer to have written a non-idiomatic pattern — passing untrusted, request-derived input directly into a transition directive. Astro applications that do not route untrusted input into these directives are unaffected. This issue has been fixed in version 7.0.4.
View original CVE JSON
{
"id": "CVE-2026-59727",
"sourceIdentifier": "[email protected]",
"published": "2026-07-27T20:16:40.153",
"lastModified": "2026-10-24T13:10:00.147",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Astro is a web framework for content-driven websites. In versions 3.10.0 through 7.0.3, when a transition:persist, transition:scope, or transition:persist-props directive is applied to a client-hydrated (client:*) component, Astro copied the directive value onto the rendered <astro-island> element without HTML-escaping it. If a developer reflects attacker-controlled input into one of these directives, an attacker can break out of the attribute and inject arbitrary HTML/JavaScript into the server-rendered output, resulting in reflected cross-site scripting (XSS). Exploitation requires the application developer to have written a non-idiomatic pattern — passing untrusted, request-derived input directly into a transition directive. Astro applications that do not route untrusted input into these directives are unaffected. This issue has been fixed in version 7.0.4."
},
{
"lang": "es",
"value": "Astro es un framework web para sitios web basados en contenido. En las versiones 3.10.0 a 7.0.3, cuando una directiva transition:persist, transition:scope o transition:persist-props se aplica a un componente hidratado por el cliente (client:*), Astro copiaba el valor de la directiva en el elemento [astro-island] renderizado sin escapar el HTML. Si un desarrollador refleja entrada controlada por el atacante en una de estas directivas, un atacante puede salir del atributo e inyectar HTML/JavaScript arbitrario en la salida renderizada por el servidor, lo que resulta en cross-site scripting (XSS) reflejado. La explotación requiere que el desarrollador de la aplicación haya escrito un patrón no idiomático - pasando entrada no confiable, derivada de la solicitud, directamente a una directiva de transición. Las aplicaciones Astro que no dirigen entrada no confiable a estas directivas no se ven afectadas. Este problema ha sido solucionado en la versión 7.0.4."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "withastro",
"product": "astro",
"versions": [
{
"version": ">= 3.10.0, < 7.0.4",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"baseScore": 2.1,
"baseSeverity": "LOW",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"privilegesRequired": "NONE",
"userInteraction": "ACTIVE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"subConfidentialityImpact": "LOW",
"subIntegrityImpact": "LOW",
"subAvailabilityImpact": "NONE",
"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-07-28T15:08:17.872331Z",
"id": "CVE-2026-59727",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-79"
},
{
"lang": "en",
"value": "CWE-83"
},
{
"lang": "en",
"value": "CWE-116"
}
]
}
],
"references": [
{
"url": "https://github.com/withastro/astro/commit/7ba0bb1dc7516e88caff9abd7767322af44b0294",
"source": "[email protected]"
},
{
"url": "https://github.com/withastro/astro/pull/17212",
"source": "[email protected]"
},
{
"url": "https://github.com/withastro/astro/releases/tag/[email protected]",
"source": "[email protected]"
},
{
"url": "https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2",
"source": "[email protected]"
},
{
"url": "https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
]
}