CVE-2026-106557
Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
- Base score: 7.7
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.30%
- Percentile among all scored CVEs: 21
- Score date: 10/17/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
🎯 ATT&CK techniques
How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.
- Exploitation
T1210Exploitation of Remote Serviceslateral movement75 % - Primary impact
T1005Data from Local Systemcollection80 %
AV:N/PR:L sin UI:R → T1210 (servicio remoto con privilegios). La falta de validación de configuración permite acceder a recursos fuera del límite (T1005: lectura de datos backend/red interna) y potencialmente actuar como proxy hacia recursos internos (T1090).
Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.
🛡️ ATT&CK mitigations that cover these techniques
Affected technologies (1)
⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.
CWEs
- CWE-22, CWE-918
References
- https://github.com/backstage/backstage/commit/017ace52d9b327ededc6704cf17799c875ae0f29
- https://github.com/backstage/backstage/commit/2d9de4ca117a529de4b6ed7dfb7aa507ca7b3f91
- https://github.com/backstage/backstage/releases/tag/v1.50.5
- https://github.com/backstage/backstage/releases/tag/v1.54.6
- https://github.com/backstage/backstage/security/advisories/GHSA-f7v3-xhm6-w245
Raw JSON (NVD)
Show
{
"id": "CVE-2026-106557",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-106557",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-10-07T17:47:07.050445Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 7.7,
"attackVector": "NETWORK",
"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": "backstage",
"product": "backstage",
"versions": [
{
"status": "affected",
"version": "< 1.50.5"
},
{
"status": "affected",
"version": ">= 1.51.0-next.0, < 1.54.6"
}
]
},
{
"vendor": "@backstage",
"product": "plugin-techdocs-node",
"versions": [
{
"status": "affected",
"version": "< 1.14.6"
},
{
"status": "affected",
"version": ">= 1.15.0, < 1.15.4"
}
]
}
]
}
],
"published": "2026-10-07T17:16:50.900",
"references": [
{
"url": "https://github.com/backstage/backstage/commit/017ace52d9b327ededc6704cf17799c875ae0f29",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/backstage/backstage/commit/2d9de4ca117a529de4b6ed7dfb7aa507ca7b3f91",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/backstage/backstage/releases/tag/v1.50.5",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/backstage/backstage/releases/tag/v1.54.6",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/backstage/backstage/security/advisories/GHSA-f7v3-xhm6-w245",
"source": "security-advisories@github.com"
}
],
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-22"
},
{
"lang": "en",
"value": "CWE-918"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later."
}
],
"lastModified": "2026-10-08T21:33:42.423",
"sourceIdentifier": "security-advisories@github.com"
}