CVE-2026-59933
PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In versions 4.0.0 through 5.8.0, 3.3.0 through 3.10.6, 2.2.0 through 2.4.6, 2.0.0 through 2.1.17, and all releases up to and including 1.30.5, the OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed .xls/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, OLERead::read() appends the same sector data repeatedly until the PHP process exhausts memory.
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This is reachable from Reader\Xls::canRead() and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file. This issue has been fixed in versions 5.8.1, 3.10.7, 2.4.7, 2.1.18 and 1.30.6.
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: 0.70%
- Percentil entre todas las CVEs puntuadas: 52
- 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 access95 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
AV:N/PR:N/UI:N indica explotación remota sin privilegios (T1190). CWE-400/835 y exhaución de memoria por archivo malformado = denegación de servicio de aplicación (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
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-400, CWE-835
Referencias
- https://github.com/PHPOffice/PhpSpreadsheet/commit/85f2556b0bf5269061bf45932ecda8a128d81750
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/1.30.6
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.1.18
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.4.7
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.7
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.8.1
- https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-xh5m-36r6-47m3
- https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-xh5m-36r6-47m3
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-59933",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-59933",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-07-28T17:57:16.033236Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"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",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "PHPOffice",
"product": "PhpSpreadsheet",
"versions": [
{
"status": "affected",
"version": ">= 4.0.0, < 5.8.1"
},
{
"status": "affected",
"version": ">= 3.3.0, < 3.10.7"
},
{
"status": "affected",
"version": ">= 2.2.0, < 2.4.7"
},
{
"status": "affected",
"version": ">= 2.0.0, < 2.1.18"
},
{
"status": "affected",
"version": "< 1.30.6"
}
]
}
]
}
],
"published": "2026-07-28T18:17:23.033",
"references": [
{
"url": "https://github.com/PHPOffice/PhpSpreadsheet/commit/85f2556b0bf5269061bf45932ecda8a128d81750",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/1.30.6",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.1.18",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.4.7",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.7",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.8.1",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-xh5m-36r6-47m3",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-xh5m-36r6-47m3",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-400"
},
{
"lang": "en",
"value": "CWE-835"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In versions 4.0.0 through 5.8.0, 3.3.0 through 3.10.6, 2.2.0 through 2.4.6, 2.0.0 through 2.1.17, and all releases up to and including 1.30.5, the OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed .xls/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, OLERead::read() appends the same sector data repeatedly until the PHP process exhausts memory. This is reachable from Reader\\Xls::canRead() and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file. This issue has been fixed in versions 5.8.1, 3.10.7, 2.4.7, 2.1.18 and 1.30.6."
}
],
"lastModified": "2026-07-30T19:19:45.637",
"sourceIdentifier": "security-advisories@github.com"
}