CVE-2026-55210
Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.2, Joplin Server's UserModel.ssoLogin() returns an existing account matched by an IdP-asserted email without checking the account's is_external flag. In deployments using mixed local and SAML authentication, an attacker whose IdP session can assert a local user's email can pass POST /api/saml, receive a session for that local account, and access or modify the victim's notes, files, and settings without knowing the local password. This issue is fixed in version 3.7.2.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- Puntuación base: 7.4
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.48%
- Percentil entre todas las CVEs puntuadas: 39
- Fecha de la puntuación: 4/10/2026
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
T1078Valid Accountsstealth · persistence · privilege escalation · initial access90 % - Impacto secundario
T1565.001Stored Data Manipulationimpact75 %
Explotación de aplicación web expuesta (AV:N). Autenticación SAML sin validar flag is_external permite suplantación de cuenta local y acceso a notas/archivos del usuario víctima.
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-290
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-55210",
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"metrics": {
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{
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"ssvcData": {
"id": "CVE-2026-55210",
"role": "CISA Coordinator",
"options": [
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"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-09-22T13:06:34.047429Z"
}
}
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"cvssMetricV31": [
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"version": "3.1",
"baseScore": 7.4,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.2,
"exploitabilityScore": 2.2
}
]
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"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "laurent22",
"product": "joplin",
"versions": [
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"status": "affected",
"version": "< 3.7.2"
}
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"published": "2026-09-21T22:16:56.890",
"references": [
{
"url": "https://github.com/laurent22/joplin/commit/b6d69d072919cbe769234f93d95ed21e1ec129b2",
"source": "security-advisories@github.com"
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{
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"source": "security-advisories@github.com"
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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 3.7.2, Joplin Server's UserModel.ssoLogin() returns an existing account matched by an IdP-asserted email without checking the account's is_external flag. In deployments using mixed local and SAML authentication, an attacker whose IdP session can assert a local user's email can pass POST /api/saml, receive a session for that local account, and access or modify the victim's notes, files, and settings without knowing the local password. This issue is fixed in version 3.7.2."
}
],
"lastModified": "2026-09-23T18:30:42.573",
"sourceIdentifier": "security-advisories@github.com"
}