High
Backstage: Improper validation of MkDocs theme configuration in TechDocs
Type: advisorySources: OSV
Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in mkdocs.yml that cause arbitrary code execution during the documentation build process. This issue is fixed in versions 1.14.6 and 1.15.4.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-106509
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 07:27 UTC · Revision 1
Source evidence
Backstage: Improper validation of MkDocs theme configuration in TechDocs
core-osv · Original sourcePublished 6 Oct 2026, 21:50 UTC
Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in mkdocs.yml that cause arbitrary code execution during the documentation build process. This issue is fixed in versions 1.14.6 and 1.15.4.
osv:CVE-2026-106509
Complete source record
{
"id": "8c474184ce7c01586d11886d95cd39e5ff68cdc3ec14684445362b8eb20bd776",
"url": "https://osv.dev/vulnerability/CVE-2026-106509",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Backstage: Improper validation of MkDocs theme configuration in TechDocs",
"summary": "Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in mkdocs.yml that cause arbitrary code execution during the documentation build process. This issue is fixed in versions 1.14.6 and 1.15.4.",
"evidence": "osv:CVE-2026-106509",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-106509",
"aliases": [
"CVE-2026-106509",
"GHSA-8w7q-29mw-gf5c"
],
"metrics": [
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"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L"
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-106509.json"
}
}
],
"modified": "2026-10-28T02:30:26.877436476Z",
"provider": "osv",
"references": [
"https://github.com/backstage/backstage/releases/tag/v1.50.5",
"https://github.com/backstage/backstage/releases/tag/v1.54.6",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/106xxx/CVE-2026-106509.json",
"https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c",
"https://nvd.nist.gov/vuln/detail/CVE-2026-106509",
"https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb",
"https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d"
],
"provider_metadata": {
"cwe_ids": [
"CWE-1336",
"CWE-94"
],
"cna_assigner": "GitHub_M",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"fixed": "1.14.6"
},
{
"introduced": "1.15.0"
},
{
"fixed": "1.15.4"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/106xxx/CVE-2026-106509.json"
}
},
"related_cves": [
{
"value": "CVE-2026-106509",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 493340,
"published_at": "2026-10-06T21:50:07.721+00:00"
}