CVE-2026-106456
Backstage is an open framework for building developer portals. From 0.5.0 until 0.6.18, the @backstage/plugin-proxy-backend package is affected by inconsistent credential enforcement for overlapping proxy routes. An operator can configure overlapping proxy paths with different credential requirements. When a parent path permits unauthenticated access and a nested path requires credentials, the parent exemption can also cover requests handled by the nested proxy. An unauthenticated caller may therefore reach the nested upstream through Backstage, including with static upstream credentials configured for that proxy. This issue is fixed in version 0.6.18.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
- Puntuación base: 4.8
Probabilidad de explotación (EPSS)
FIRST aún no ha puntuado esta CVE (habitual en CVEs muy recientes o rechazadas).
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
T1078Valid Accountsstealth · persistence · privilege escalation · initial access80 % - Impacto secundario
T1552.007Container APIcredential access70 %
Acceso remoto sin autenticación a rutas proxy anidadas (AV:N, PR:N, UI:N) mediante inconsistencia en validación de credenciales; exposición de credenciales estáticas configuradas aguas arriba.
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-863
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-106456",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 4.8,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 2.5,
"exploitabilityScore": 2.2
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "backstage",
"product": "backstage",
"versions": [
{
"status": "affected",
"version": ">= 1.28.0, < 1.55.0"
}
]
},
{
"vendor": "@backstage",
"product": "plugin-proxy-backend",
"versions": [
{
"status": "affected",
"version": ">= 0.5.0, < 0.6.18"
}
]
}
]
}
],
"published": "2026-10-06T21:17:15.903",
"references": [
{
"url": "https://github.com/backstage/backstage/commit/9df92923ac32558bb80edeceafd8de780c44e218",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/backstage/backstage/releases/tag/v1.55.0",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/backstage/backstage/security/advisories/GHSA-472h-9c5j-prrr",
"source": "security-advisories@github.com"
}
],
"vulnStatus": "Received",
"weaknesses": [
{
"type": "Primary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-863"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Backstage is an open framework for building developer portals. From 0.5.0 until 0.6.18, the @backstage/plugin-proxy-backend package is affected by inconsistent credential enforcement for overlapping proxy routes. An operator can configure overlapping proxy paths with different credential requirements. When a parent path permits unauthenticated access and a nested path requires credentials, the parent exemption can also cover requests handled by the nested proxy. An unauthenticated caller may therefore reach the nested upstream through Backstage, including with static upstream credentials configured for that proxy. This issue is fixed in version 0.6.18."
}
],
"lastModified": "2026-10-06T21:17:15.903",
"sourceIdentifier": "security-advisories@github.com"
}