CVE-2026-78659
Estado: Pendiente de análisisAlta (7.5)—
Cuando un cliente envía cabeceras "Trailer", el servidor HTTP utiliza internamente los valores de la cabecera para rellenar el mapa Request.Trailer que se pasa al manejador del servidor. Como Request.Trailer es un mapa, cada entrada conlleva una sobrecarga de memoria. En los servidores HTTP/2, un cliente malicioso puede aprovechar esto enviando una cabecera "Trailer" que declare un gran número de campos, haciendo que el servidor asigne una cantidad desproporcionada de memoria mientras elude los límites Server.MaxHeaderValueCount y Server.MaxHeaderBytes. Este exploit no es aplicable a los servidores HTTP/1, que no admiten la multiplexación de un gran número de solicitudes sobre una única conexión TCP y cuyo Server.MaxHeaderBytes se calcula de forma diferente.
Traducción automática del texto original de NVD (en inglés).
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: 0.57%
- Percentil entre todas las CVEs puntuadas: 46
- Fecha de la puntuación: 14/10/2026
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.
- Explotación
T1190Exploit Public-Facing Applicationinitial access95 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
Servidor HTTP/2 expuesto en red sin autenticación (AV:N, PR:N) vulnerable a ataque de denegación de servicio mediante exhaustión de memoria por cabeceras 'Trailer' malformadas.
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
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-405
Referencias
JSON original (NVD)
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{
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{
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{
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{
"name": "pseudoHeaderError.Error"
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{
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},
{
"name": "serverConn.Flush"
},
{
"name": "stickyErrWriter.Write"
},
{
"name": "transportResponseBody.Close"
},
{
"name": "transportResponseBody.Read"
},
{
"name": "unencryptedTransport.RoundTrip"
},
{
"name": "writeData.String"
}
]
}
]
}
],
"published": "2026-10-08T23:17:03.270",
"references": [
{
"url": "https://go.dev/cl/847185",
"source": "security@golang.org"
},
{
"url": "https://go.dev/cl/847314",
"source": "security@golang.org"
},
{
"url": "https://go.dev/issue/81857",
"source": "security@golang.org"
},
{
"url": "https://groups.google.com/g/golang-announce/c/U2fTuyDJznI",
"source": "security@golang.org"
},
{
"url": "https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs",
"source": "security@golang.org"
},
{
"url": "https://pkg.go.dev/vuln/GO-2026-6603",
"source": "security@golang.org"
}
],
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"description": [
{
"lang": "en",
"value": "CWE-405"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "When \"Trailer\" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a \"Trailer\" header that declares a large number of fields, causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently."
}
],
"lastModified": "2026-10-09T16:35:35.900",
"sourceIdentifier": "security@golang.org"
}