CVE-2020-26287
HedgeDoc es una plataforma colaborativa para escribir y compartir rebajas. En HedgeDoc versiones anteriores a 1.7.1, un atacante puede inyectar etiquetas "script" arbitrarias en las notas de HedgeDoc usando diagramas mermaid. Nuestra política de seguridad de contenido evita una carga de scripts de la mayoría de las ubicaciones, pero se permite "www.google-analytics.com" Usando Google Tag Manager, es posible inyectar JavaScript arbitrario y ejecutarlo al cargar la página. Dependiendo de la configuración de la instancia, es posible que el atacante no necesite autenticación para crear o editar notas. El problema está parcheado en HedgeDoc versión 1.7.1. Como solución alternativa, se puede rechazar "www.google-analytics.com" en el encabezado "Content-Security-Policy". Tome en cuenta que pueden presentar otras formas de aprovechar la inyección de etiquetas "script"
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- Puntuación base: 8.7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 1.46%
- Percentil entre todas las CVEs puntuadas: 73
- Fecha de la puntuación: 9/10/2026
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 (1)
CWE
- CWE-79
- CWE-79
Referencias
- https://github.com/Alemmi/ctf-writeups/blob/main/hxpctf-2020/hackme/solution.md
- https://github.com/hackmdio/codimd/issues/1630
- https://github.com/hedgedoc/hedgedoc/commit/58276ebbf4504a682454a3686dcaff88bc1069d4
- https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1
- https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-g6w6-7xf9-m95p
- https://github.com/Alemmi/ctf-writeups/blob/main/hxpctf-2020/hackme/solution.md
- https://github.com/hackmdio/codimd/issues/1630
- https://github.com/hedgedoc/hedgedoc/commit/58276ebbf4504a682454a3686dcaff88bc1069d4
- https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1
- https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-g6w6-7xf9-m95p
JSON original (NVD)
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{
"id": "CVE-2020-26287",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 4.3,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N",
"authentication": "NONE",
"integrityImpact": "PARTIAL",
"accessComplexity": "MEDIUM",
"availabilityImpact": "NONE",
"confidentialityImpact": "NONE"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 8.6,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": true
}
],
"cvssMetricV31": [
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"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.8,
"exploitabilityScore": 2.3
},
{
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"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
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"confidentialityImpact": "HIGH"
},
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}
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"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
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"vendor": "hedgedoc",
"product": "hedgedoc",
"versions": [
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"status": "affected",
"version": "< 1.7.1"
}
]
}
]
}
],
"published": "2020-12-29T00:15:12.673",
"references": [
{
"url": "https://github.com/Alemmi/ctf-writeups/blob/main/hxpctf-2020/hackme/solution.md",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/hackmdio/codimd/issues/1630",
"tags": [
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{
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{
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"tags": [
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{
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{
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"tags": [
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"source": "af854a3a-2127-422b-91ae-364da2661108"
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],
"vulnStatus": "Modified",
"weaknesses": [
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"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-79"
}
]
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{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
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"value": "CWE-79"
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]
}
],
"descriptions": [
{
"lang": "en",
"value": "HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1 an attacker can inject arbitrary `script` tags in HedgeDoc notes using mermaid diagrams. Our content security policy prevents loading scripts from most locations, but `www.google-analytics.com` is allowed. Using Google Tag Manger it is possible to inject arbitrary JavaScript and execute it on page load. Depending on the configuration of the instance, the attacker may not need authentication to create or edit notes. The problem is patched in HedgeDoc 1.7.1. As a workaround one can disallow `www.google-analytics.com` in the `Content-Security-Policy` header. Note that other ways to leverage the `script` tag injection might exist."
},
{
"lang": "es",
"value": "HedgeDoc es una plataforma colaborativa para escribir y compartir rebajas. En HedgeDoc versiones anteriores a 1.7.1, un atacante puede inyectar etiquetas \"script\" arbitrarias en las notas de HedgeDoc usando diagramas mermaid. Nuestra política de seguridad de contenido evita una carga de scripts de la mayoría de las ubicaciones, pero se permite \"www.google-analytics.com\" Usando Google Tag Manager, es posible inyectar JavaScript arbitrario y ejecutarlo al cargar la página. Dependiendo de la configuración de la instancia, es posible que el atacante no necesite autenticación para crear o editar notas. El problema está parcheado en HedgeDoc versión 1.7.1. Como solución alternativa, se puede rechazar \"www.google-analytics.com\" en el encabezado \"Content-Security-Policy\". Tome en cuenta que pueden presentar otras formas de aprovechar la inyección de etiquetas \"script\""
}
],
"lastModified": "2026-06-17T03:08:00.227",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:hedgedoc:hedgedoc:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DB55BE58-3D3F-40C5-89FE-2AACEA56F4E0",
"versionEndExcluding": "1.7.1"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "security-advisories@github.com"
}