CVE-2026-103388
MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.
When another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.
Preconditions:
- Attacker must hold galaxy editor privileges (local or via sync).
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- Victim must view the affected cluster and click the malicious link.
Impact:
- Stored cross-site scripting (XSS) in the victim's browser.
- Potential session theft, credential harvesting, or unauthorized actions within the MISP application.
Affected: <2.5.48.
CVSS
- Versión: 4.0
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Puntuación base: 6.2
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.24%
- Percentil entre todas las CVEs puntuadas: 14
- 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).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1189Drive-by Compromiseinitial access90 % - Impacto principal
T1059.007JavaScriptexecution85 % - Impacto secundario
T1041Exfiltration Over C2 Channelexfiltration75 % - Impacto secundario
T1187Forced Authenticationcredential access70 %
XSS almacenado (CWE-79) mediante URL javascript: en campo Galaxy Cluster. Requiere interacción del usuario (clic) y privilegios previos (galaxy editor). Permite ejecución de script, exfiltración de datos y secuestro de sesión en contexto de navegador.
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-2026-103388",
"cveTags": [],
"metrics": {
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{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-103388",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
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],
"version": "2.0.3",
"timestamp": "2026-09-30T14:58:39.451751Z"
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"type": "Secondary",
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"version": "4.0",
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"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "ACTIVE",
"attackComplexity": "LOW",
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"subIntegrityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
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"subConfidentialityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
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"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
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"modifiedSubConfidentialityImpact": "NOT_DEFINED",
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"affected": [
{
"source": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
"affectedData": [
{
"cpes": [
"cpe:2.3:a:misp:misp:*:*:*:*:*:*:*:*"
],
"repo": "https://github.com/MISP/MISP",
"vendor": "MISP",
"modules": [
"GalaxyClusters view (default theme)",
"GalaxyClusters view (Overmind theme)"
],
"product": "MISP",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "2.5.48",
"versionType": "semver"
}
],
"programFiles": [
"app/View/GalaxyClusters/view.ctp",
"app/View/Themed/Overmind/Elements/GalaxyClusters/View/galaxy_clusters_general.ctp"
]
}
]
}
],
"published": "2026-09-30T15:22:27.143",
"references": [
{
"url": "https://github.com/MISP/MISP/commit/118528767",
"source": "5a6e4751-2f3f-4070-9419-94fb35b644e8"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
"description": [
{
"lang": "en",
"value": "CWE-79"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.\n\nWhen another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.\n\nPreconditions:\n\n- Attacker must hold galaxy editor privileges (local or via sync).\n\n- Victim must view the affected cluster and click the malicious link.\n\nImpact:\n\n- Stored cross-site scripting (XSS) in the victim's browser.\n\n- Potential session theft, credential harvesting, or unauthorized actions within the MISP application.\n\nAffected: <2.5.48."
}
],
"lastModified": "2026-09-30T16:17:08.983",
"sourceIdentifier": "5a6e4751-2f3f-4070-9419-94fb35b644e8"
}