CVE-2026-6103
phar_tar_number() parses the octal size field of a TAR header into a uint32_t with no overflow check. The field is 11 octal digits wide and holds values up to 0x1FFFFFFFF, so a size above 0xFFFFFFFF silently wraps. The parser then skips the wrong number of data blocks and interprets attacker-controlled file content as the next TAR header, which lets a crafted archive inject entries that PharData reports and extracts as if they were genuine.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- Puntuación base: 4.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.17%
- Percentil entre todas las CVEs puntuadas: 5
- 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.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation45 % - Impacto principal
T1565.001Stored Data Manipulationimpact75 % - Impacto secundario
T1036.005Match Legitimate Resource Name or Locationstealth60 %
CVE-2026-6103 en PHP permite manipulación de archivos TAR mediante desbordamiento de entero (CWE-190), inyectando entradas falsas sin privilegios elevados. AV:L indica acceso local; el desbordamiento permite evasión de seguridad (I:L). No hay ejecución de código confirmada.
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-190
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-6103",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-6103",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-25T20:41:05.626504Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security@php.net",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 4.3,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 1.4,
"exploitabilityScore": 2.5
}
]
},
"affected": [
{
"source": "security@php.net",
"affectedData": [
{
"vendor": "PHP Group",
"product": "PHP",
"versions": [
{
"status": "affected",
"version": "8.2.*",
"lessThan": "8.2.34",
"versionType": "semver"
},
{
"status": "affected",
"version": "8.3.*",
"lessThan": "8.3.35",
"versionType": "semver"
},
{
"status": "affected",
"version": "8.4.*",
"lessThan": "8.4.26",
"versionType": "semver"
},
{
"status": "affected",
"version": "8.5.*",
"lessThan": "8.5.11",
"versionType": "semver"
}
],
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-09-25T21:17:23.790",
"references": [
{
"url": "https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85",
"source": "security@php.net"
},
{
"url": "https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "security@php.net",
"description": [
{
"lang": "en",
"value": "CWE-190"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "phar_tar_number() parses the octal size field of a TAR header into a uint32_t with no overflow check. The field is 11 octal digits wide and holds values up to 0x1FFFFFFFF, so a size above 0xFFFFFFFF silently wraps. The parser then skips the wrong number of data blocks and interprets attacker-controlled file content as the next TAR header, which lets a crafted archive inject entries that PharData reports and extracts as if they were genuine."
}
],
"lastModified": "2026-09-29T21:27:41.130",
"sourceIdentifier": "security@php.net"
}