CVE-2026-9516
Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws.
To skip a leading 3-byte UTF-8 BOM, decode_json() advances the input scalar's string pointer past the mark with SvPV_set() and restores it only on the normal return path. When decoding aborts through a Perl exception, for example a filter_json_object callback that croaks, the restore is skipped and the scalar is left with its string pointer offset into its own buffer and a shortened length.
When that scalar is later freed, the allocator receives an invalid pointer and the interpreter aborts. A single BOM prefixed document decoded with a throwing filter callback crashes any caller.
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: 0.62%
- Percentil entre todas las CVEs puntuadas: 48
- Fecha de la puntuación: 5/10/2026
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 access85 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
Vulnerabilidad de DoS remota en librería Perl accesible sin autenticación (AV:N, PR:N, UI:N). Entrada UTF-8 malformada causa crash del intérprete. CWE-755 (excepción no manejada).
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)
CWE
- CWE-755, CWE-763
Referencias
JSON original (NVD)
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"id": "CVE-2026-9516",
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"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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"role": "CISA Coordinator",
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"version": "2.0.3",
"timestamp": "2026-06-03T15:58:42.977647Z"
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"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
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"repo": "https://github.com/rurban/Cpanel-JSON-XS",
"vendor": "RURBAN",
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"programFiles": [
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"published": "2026-06-03T01:16:23.430",
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"descriptions": [
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"lang": "en",
"value": "Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws.\n\nTo skip a leading 3-byte UTF-8 BOM, decode_json() advances the input scalar's string pointer past the mark with SvPV_set() and restores it only on the normal return path. When decoding aborts through a Perl exception, for example a filter_json_object callback that croaks, the restore is skipped and the scalar is left with its string pointer offset into its own buffer and a shortened length.\n\nWhen that scalar is later freed, the allocator receives an invalid pointer and the interpreter aborts. A single BOM prefixed document decoded with a throwing filter callback crashes any caller."
},
{
"lang": "es",
"value": "Las versiones de Cpanel::JSON::XS anteriores a la 4.41 para Perl permiten la denegación de servicio a través de una entrada prefijada con BOM UTF-8 cuando una devolución de llamada de filtro de decodificación lanza una excepción.\n\nPara omitir un BOM UTF-8 inicial de 3 bytes, decode_json() avanza el puntero de cadena del escalar de entrada más allá de la marca con SvPV_set() y lo restaura solo en la ruta de retorno normal. Cuando la decodificación se aborta a través de una excepción de Perl, por ejemplo, una devolución de llamada filter_json_object que falla, la restauración se omite y el escalar queda con su puntero de cadena desplazado dentro de su propio búfer y una longitud acortada.\n\nCuando ese escalar se libera posteriormente, el asignador recibe un puntero no válido y el intérprete se aborta. Un único documento prefijado con BOM decodificado con una devolución de llamada de filtro que lanza una excepción bloquea a cualquier llamador."
}
],
"lastModified": "2026-07-22T19:10:00.120",
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{
"nodes": [
{
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