CVE-2026-55105
Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, packages/renderer/MdToHtml/rules/fountain.ts passes HTML generated by the vendored fountain.js renderer into note output without sanitizing it. A malicious Fountain code block can therefore execute script when Fountain rendering is enabled in desktop or mobile clients, or when a note is published through Joplin Server where Fountain rendering is enabled by default. The script can read content subsequently loaded in the reused note viewer or, when published notes are served from the same domain as server content, access data available to an authenticated browser in the server origin. This issue is fixed in versions 3.6.15 and 3.7.2.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
- Puntuación base: 7.7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.50%
- Percentil entre todas las CVEs puntuadas: 40
- 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 access85 % - Impacto principal
T1059.007JavaScriptexecution80 % - Impacto secundario
T1005Data from Local Systemcollection75 %
Joplin antes de 3.6.15/3.7.2 ejecuta JavaScript desde bloques Fountain no sanitizados (T1190: app expuesta en web/servidor); permite T1059.007 (ejecución de script) y T1005 (lectura de contenido de notas). AV:N, PR:L, UI:N confirman explotación remota con autenticación.
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-79
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-55105",
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"metrics": {
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{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-55105",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-24T22:47:41.163511Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
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"baseScore": 7.7,
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"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 4,
"exploitabilityScore": 3.1
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "laurent22",
"product": "joplin",
"versions": [
{
"status": "affected",
"version": "< 3.6.15"
},
{
"status": "affected",
"version": ">= 3.7.0, < 3.7.2"
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"published": "2026-09-21T21:17:05.320",
"references": [
{
"url": "https://github.com/laurent22/joplin/commit/8e0812de9d79d1f0698bb76a8c5d7e991df9748d",
"source": "security-advisories@github.com"
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{
"url": "https://github.com/laurent22/joplin/pull/15659",
"source": "security-advisories@github.com"
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{
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"description": [
{
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"descriptions": [
{
"lang": "en",
"value": "Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, packages/renderer/MdToHtml/rules/fountain.ts passes HTML generated by the vendored fountain.js renderer into note output without sanitizing it. A malicious Fountain code block can therefore execute script when Fountain rendering is enabled in desktop or mobile clients, or when a note is published through Joplin Server where Fountain rendering is enabled by default. The script can read content subsequently loaded in the reused note viewer or, when published notes are served from the same domain as server content, access data available to an authenticated browser in the server origin. This issue is fixed in versions 3.6.15 and 3.7.2."
}
],
"lastModified": "2026-09-24T23:17:11.490",
"sourceIdentifier": "security-advisories@github.com"
}