CVE-2026-104721
Path-traversal vulnerability in QOS.CH Sarl Logback-classic on Java (logback-classic module) allows path-traversal vulnerability. More specifically, an MDC-based discriminator value flows unsanitized into a nested FileAppender path, letting an attacker who influences that MDC value (e.g. via an HTTP header) create and append log files outside the intended directory.
This issue affects Logback-classic: from 0.9.14 through 1.6.4. This vulnerability is similar to CVE-2026-19880 but involves other attack techniques.
CVSS
- Versión: 4.0
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/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:P/AU:N/R:X/V:X/RE:M/U:Green
- Puntuación base: 6.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.33%
- Percentil entre todas las CVEs puntuadas: 24
- 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
T1190Exploit Public-Facing Applicationinitial access75 % - Impacto principal
T1005Data from Local Systemcollection70 % - Impacto secundario
T1565.001Stored Data Manipulationimpact65 %
AV:N sin autenticación: aplicación expuesta en red (T1190). MDC via HTTP header permite lectura fuera del directorio (T1005) y manipulación de archivos log (T1565.001).
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-22
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-104721",
"cveTags": [],
"metrics": {
"cvssMetricV40": [
{
"type": "Secondary",
"source": "vulnerability@ncsc.ch",
"cvssData": {
"Safety": "PRESENT",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 6.3,
"Automatable": "NO",
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/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:P/AU:N/R:X/V:X/RE:M/U:Green",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "GREEN",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "LOW",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "LOW",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "LOW",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "MODERATE",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
}
}
]
},
"affected": [
{
"source": "vulnerability@ncsc.ch",
"affectedData": [
{
"vendor": "QOS.CH Sarl",
"modules": [
"logback-classic"
],
"product": "Logback-classic",
"versions": [
{
"status": "affected",
"version": "0.9.14",
"versionType": "maven",
"lessThanOrEqual": "1.6.4"
},
{
"status": "unaffected",
"version": "1.6.5",
"versionType": "maven"
}
],
"platforms": [
"Java"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-02T14:17:10.167",
"references": [
{
"url": "https://logback.qos.ch/news.html#1.6.5",
"source": "vulnerability@ncsc.ch"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "vulnerability@ncsc.ch",
"description": [
{
"lang": "en",
"value": "CWE-22"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Path-traversal vulnerability in QOS.CH Sarl Logback-classic on Java (logback-classic module) allows path-traversal vulnerability. More specifically, an \nMDC-based discriminator value flows unsanitized into a nested \nFileAppender path, letting an attacker who influences that MDC value \n(e.g. via an HTTP header)\n create and append log files outside the intended directory. \n\n\nThis issue affects Logback-classic: from 0.9.14 through 1.6.4. This vulnerability is similar to CVE-2026-19880 but involves other attack techniques."
}
],
"lastModified": "2026-10-02T17:59:09.430",
"sourceIdentifier": "vulnerability@ncsc.ch"
}