CVE-2020-26237
Highlight.js is a syntax highlighter written in JavaScript. Highlight.js versions before 9.18.2 and 10.1.2 are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in prototype pollution of the base object's prototype during highlighting. If you allow users to insert custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter the language names the user can provide you may be vulnerable.
Leer descripción completaMostrar menos
The pollution should just be harmless data but this can cause problems for applications not expecting these properties to exist and can result in strange behavior or application crashes, i.e. a potential DOS vector. If your website or application does not render user provided data it should be unaffected. Versions 9.18.2 and 10.1.2 and newer include fixes for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H
- Puntuación base: 8.7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 1.32%
- Percentil entre todas las CVEs puntuadas: 70
- 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).
Tecnologías afectadas (3)
CWE
- CWE-471
Referencias
- https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0
- https://github.com/highlightjs/highlight.js/pull/2636
- https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx
- https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html
- https://www.npmjs.com/package/highlight.js
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0
- https://github.com/highlightjs/highlight.js/pull/2636
- https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx
- https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html
- https://www.npmjs.com/package/highlight.js
- https://www.oracle.com/security-alerts/cpujul2022.html
JSON original (NVD)
Mostrar
{
"id": "CVE-2020-26237",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 4.9,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:M/Au:S/C:N/I:P/A:P",
"authentication": "SINGLE",
"integrityImpact": "PARTIAL",
"accessComplexity": "MEDIUM",
"availabilityImpact": "PARTIAL",
"confidentialityImpact": "NONE"
},
"acInsufInfo": false,
"impactScore": 4.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 6.8,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": true
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 5.8,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:N",
"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 4,
"exploitabilityScore": 1.3
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 8.7,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 5.8,
"exploitabilityScore": 2.3
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "highlightjs",
"product": "highlight.js",
"versions": [
{
"status": "affected",
"version": "< 9.18.2"
},
{
"status": "affected",
"version": ">= 10.0.0, < 10.1.2"
}
]
}
]
}
],
"published": "2020-11-24T23:15:11.223",
"references": [
{
"url": "https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0",
"tags": [
"Patch",
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/highlightjs/highlight.js/pull/2636",
"tags": [
"Patch",
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx",
"tags": [
"Mitigation",
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html",
"tags": [
"Mailing List",
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://www.npmjs.com/package/highlight.js",
"tags": [
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://www.oracle.com/security-alerts/cpujul2022.html",
"tags": [
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0",
"tags": [
"Patch",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/highlightjs/highlight.js/pull/2636",
"tags": [
"Patch",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx",
"tags": [
"Mitigation",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html",
"tags": [
"Mailing List",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.npmjs.com/package/highlight.js",
"tags": [
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.oracle.com/security-alerts/cpujul2022.html",
"tags": [
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-471"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Highlight.js is a syntax highlighter written in JavaScript. Highlight.js versions before 9.18.2 and 10.1.2 are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in prototype pollution of the base object's prototype during highlighting. If you allow users to insert custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter the language names the user can provide you may be vulnerable. The pollution should just be harmless data but this can cause problems for applications not expecting these properties to exist and can result in strange behavior or application crashes, i.e. a potential DOS vector. If your website or application does not render user provided data it should be unaffected. Versions 9.18.2 and 10.1.2 and newer include fixes for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release."
},
{
"lang": "es",
"value": "Highlight.js es un resaltador de sintaxis escrito en JavaScript. Highlight.js versiones anteriores a 9.18.2 y 10.1.2 son vulnerables a una Contaminación de Prototipo. Un bloque de código HTML malicioso puede ser diseñado lo que resultará en la contaminación del prototipo del prototipo del objeto base durante el resaltado. Si permite a usuarios insertar bloques de código HTML personalizados en su página y aplicación por medio del análisis de bloques de código Markdown (o similar) y no filtrar los nombres del idioma que el usuario puede proporcionar, puede ser vulnerable. La contaminación debería ser solo datos inofensivos, pero esto puede causar problemas para las aplicaciones que no esperan que se presenten estas propiedades y puede resultar en un comportamiento extraño o fallos de la aplicación, es decir, un vector de DOS potencial. Si su sitio web o aplicación no proporciona los datos proporcionados por el usuario, no debería estar afectado. Versiones 9.18.2 y 10.1. 2 y más recientes incluyen correcciones para esta vulnerabilidad. Si está usando la versión 7 o 8, le recomendamos que actualice a una versión más reciente"
}
],
"lastModified": "2026-06-17T03:07:53.420",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:highlightjs:highlight.js:*:*:*:*:*:node.js:*:*",
"vulnerable": true,
"matchCriteriaId": "AF6D839E-1AC7-4F59-B516-69D5F8487ED4",
"versionEndExcluding": "9.18.2"
},
{
"criteria": "cpe:2.3:a:highlightjs:highlight.js:*:*:*:*:*:node.js:*:*",
"vulnerable": true,
"matchCriteriaId": "EE56A922-F91D-4AD1-8C07-56B25BD9E32D",
"versionEndExcluding": "10.1.2",
"versionStartIncluding": "10.1.0"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:oracle:mysql_enterprise_monitor:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6B4888C7-3A68-4AAE-A3ED-8DD4E358BCA4",
"versionEndIncluding": "8.0.30"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "security-advisories@github.com"
}