CVE-2026-29772

Estado: AnalizadaAlta (7.5)—

Astro is a web framework. Prior to version 10.0.0, Astro's Server Islands POST handler buffers and parses the full request body as JSON without enforcing a size limit. Because JSON.parse() allocates a V8 heap object for every element in the input, a crafted payload of many small JSON objects achieves ~15x memory amplification (wire bytes to heap bytes), allowing a single unauthenticated request to exhaust the process heap and crash the server. The /_server-islands/[name] route is registered on all Astro SSR apps regardless of whether any component uses server:defer, and the body is parsed before the island name is validated, so any Astro SSR app with the Node standalone adapter is affected. This issue has been patched in version 10.0.0.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 7.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.43%
Percentil entre todas las CVEs puntuadas: 35
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access95 %
Impacto principalT1499.004 Application or System Exploitationimpact90 %

Vector CVSS AV:N/AC:L/PR:N/UI:N indica explotación remota sin autenticación (T1190). CWE-770 y descripción explícita de exhaustión de heap causan DoS por consumo de recursos (T1499.004).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application Isolation and Sandboxing

Tecnologías afectadas (1)

Astro — @astrojs/node

CWE

CWE-770

Referencias

https://github.com/withastro/astro/security/advisories/GHSA-3rmj-9m5h-8fpv

JSON original (NVD)

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          "options": [
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              "automatable": "no"
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      "lang": "en",
      "value": "Astro is a web framework. Prior to version 10.0.0, Astro's Server Islands POST handler buffers and parses the full request body as JSON without enforcing a size limit. Because JSON.parse() allocates a V8 heap object for every element in the input, a crafted payload of many small JSON objects achieves ~15x memory amplification (wire bytes to heap bytes), allowing a single unauthenticated request to exhaust the process heap and crash the server. The /_server-islands/[name] route is registered on all Astro SSR apps regardless of whether any component uses server:defer, and the body is parsed before the island name is validated, so any Astro SSR app with the Node standalone adapter is affected. This issue has been patched in version 10.0.0."
    },
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      "value": "Astro es un framework web. Antes de la versión 10.0.0, el gestor POST de Server Islands de Astro almacena en búfer y analiza el cuerpo completo de la solicitud como JSON sin aplicar un límite de tamaño. Debido a que JSON.parse() asigna un objeto de pila V8 para cada elemento en la entrada, una carga útil manipulada de muchos objetos JSON pequeños logra una amplificación de memoria de ~15x (bytes en tránsito a bytes en pila), permitiendo que una única solicitud no autenticada agote la pila del proceso y bloquee el servidor. La ruta /_server-islands/[name] está registrada en todas las aplicaciones Astro SSR independientemente de si algún componente utiliza server:defer, y el cuerpo se analiza antes de que se valide el nombre de la isla, por lo que cualquier aplicación Astro SSR con el adaptador autónomo de Node se ve afectada. Este problema ha sido parcheado en la versión 10.0.0."
    }
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  "lastModified": "2026-06-17T10:29:51.450",
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