CVE-2021-40978
The mkdocs 1.2.2 built-in dev-server allows directory traversal using the port 8000, enabling remote exploitation to obtain :sensitive information. NOTE: the vendor has disputed this as described in https://github.com/mkdocs/mkdocs/issues/2601.] and https://github.com/nisdn/CVE-2021-40978/issues/1
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 15%
- Percentil entre todas las CVEs puntuadas: 97
- 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).
💥 Exploits públicos
Hay código de explotación o plantillas de detección públicos. No es lo mismo que explotación activa confirmada (KEV), pero aumenta el riesgo: parchee con prioridad.
- Plantilla de Nuclei (detección automática y masiva) · MKdocs 1.2.2 - Directory Traversal
- Prueba de concepto en GitHub (no verificada) · Lista de pruebas de concepto en GitHub
⚠️ Las pruebas de concepto de GitHub no están verificadas: algunas son falsas o contienen malware. No las ejecute nunca fuera de un laboratorio aislado.
Tecnologías afectadas (1)
CWE
- CWE-22
Referencias
- https://github.com/mkdocs/mkdocs
- https://github.com/mkdocs/mkdocs/issues/2601
- https://github.com/nisdn/CVE-2021-40978
- https://github.com/nisdn/CVE-2021-40978/issues/1
- https://github.com/mkdocs/mkdocs
- https://github.com/mkdocs/mkdocs/issues/2601
- https://github.com/nisdn/CVE-2021-40978
- https://github.com/nisdn/CVE-2021-40978/issues/1
JSON original (NVD)
Mostrar
{
"id": "CVE-2021-40978",
"cveTags": [
{
"tags": [
"disputed"
],
"sourceIdentifier": "cve@mitre.org"
}
],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-40978",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2024-07-02T18:07:46.527499Z"
}
}
],
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 5,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
"authentication": "NONE",
"integrityImpact": "NONE",
"accessComplexity": "LOW",
"availabilityImpact": "NONE",
"confidentialityImpact": "PARTIAL"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 10,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"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:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "cve@mitre.org",
"affectedData": [
{
"vendor": "n/a",
"product": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
]
}
],
"published": "2021-10-07T14:15:08.280",
"references": [
{
"url": "https://github.com/mkdocs/mkdocs",
"tags": [
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://github.com/mkdocs/mkdocs/issues/2601",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://github.com/nisdn/CVE-2021-40978",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://github.com/nisdn/CVE-2021-40978/issues/1",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://github.com/mkdocs/mkdocs",
"tags": [
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/mkdocs/mkdocs/issues/2601",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/nisdn/CVE-2021-40978",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/nisdn/CVE-2021-40978/issues/1",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-22"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "The mkdocs 1.2.2 built-in dev-server allows directory traversal using the port 8000, enabling remote exploitation to obtain :sensitive information. NOTE: the vendor has disputed this as described in https://github.com/mkdocs/mkdocs/issues/2601.] and https://github.com/nisdn/CVE-2021-40978/issues/1"
},
{
"lang": "es",
"value": "** EN DISPUTA ** El dev-server incorporado en mkdocs versión 1.2.2, permite un salto de directorios usando el puerto 8000, permitiendo una explotación remota para obtener información confidencial. NOTA: el vendedor ha rebatido esto como se describe en https://github.com/mkdocs/mkdocs/issues/2601.] y https://github.com/nisdn/CVE-2021-40978/issues/1."
}
],
"lastModified": "2026-06-17T04:07:42.017",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:mkdocs:mkdocs:1.2.2:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F35885F9-FB98-4930-AEED-17BE8A670138"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cve@mitre.org"
}