GHSA-6JR7-99PF-8VGF
Vulnerability from github – Published: 2026-02-02 20:19 – Updated: 2026-02-02 20:19Impact
When TechDocs is configured with runIn: local, a malicious actor who can submit or modify a repository's mkdocs.yml file can execute arbitrary Python code on the TechDocs build server via MkDocs hooks configuration.
Patches
Upgrade to @backstage/plugin-techdocs-node version 1.13.11, 1.14.1 or later.
The fix introduces an allowlist of supported MkDocs configuration keys. Unsupported configuration keys (including hooks) are now removed from mkdocs.yml before running the generator, with a warning logged to indicate which keys were removed.
Note: Users of @techdocs/cli should also upgrade to the latest version, which includes the fixed @backstage/plugin-techdocs-node dependency.
Workarounds
If you cannot upgrade immediately:
- Use Docker mode with restricted access: Configure TechDocs with
runIn: dockerinstead ofrunIn: local. This provides container isolation, though it does not fully mitigate the risk. - Restrict repository access: Limit who can modify
mkdocs.ymlfiles in repositories that TechDocs processes. Only allow trusted contributors. - Manual review: Implement PR review requirements for changes to
mkdocs.ymlfiles to detect malicioushooksconfigurations before they are merged. - Downgrade MkDocs: Use MkDocs < 1.4.0 (e.g., 1.3.1) which does not support hooks. Note: This may limit access to newer MkDocs features.
Note: Building documentation in CI/CD pipelines using @techdocs/cli does not mitigate this vulnerability, as the CLI uses the same vulnerable @backstage/plugin-techdocs-node package.
References
MkDocs Hooks Documentation MkDocs 1.4 Release Notes TechDocs Architecture
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@backstage/plugin-techdocs-node"
},
"ranges": [
{
"events": [
{
"introduced": "1.14.0"
},
{
"fixed": "1.14.1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.14.0"
]
},
{
"package": {
"ecosystem": "npm",
"name": "@backstage/plugin-techdocs-node"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.13.11"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-25153"
],
"database_specific": {
"cwe_ids": [
"CWE-94"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-02T20:19:58Z",
"nvd_published_at": "2026-01-30T22:15:56Z",
"severity": "HIGH"
},
"details": "### Impact\n\nWhen TechDocs is configured with `runIn: local`, a malicious actor who can submit or modify a repository\u0027s `mkdocs.yml` file can execute arbitrary Python code on the TechDocs build server via MkDocs hooks configuration.\n\n### Patches\n\nUpgrade to `@backstage/plugin-techdocs-node` version 1.13.11, 1.14.1 or later.\nThe fix introduces an allowlist of supported MkDocs configuration keys. Unsupported configuration keys (including `hooks`) are now removed from `mkdocs.yml` before running the generator, with a warning logged to indicate which keys were removed.\n\n**Note**: Users of `@techdocs/cli` should also upgrade to the latest version, which includes the fixed `@backstage/plugin-techdocs-node` dependency.\n\n### Workarounds\n\nIf you cannot upgrade immediately:\n\n1. Use Docker mode with restricted access: Configure TechDocs with `runIn: docker` instead of `runIn: local`. This provides container isolation, though it does not fully mitigate the risk.\n2. Restrict repository access: Limit who can modify `mkdocs.yml` files in repositories that TechDocs processes. Only allow trusted contributors.\n3. Manual review: Implement PR review requirements for changes to `mkdocs.yml` files to detect malicious `hooks` configurations before they are merged.\n4. Downgrade MkDocs: Use MkDocs \u003c 1.4.0 (e.g., 1.3.1) which does not support hooks. Note: This may limit access to newer MkDocs features.\n\n**Note**: Building documentation in CI/CD pipelines using `@techdocs/cli` does not mitigate this vulnerability, as the CLI uses the same vulnerable `@backstage/plugin-techdocs-node` package.\n\n### References\n\n[MkDocs Hooks Documentation](https://www.mkdocs.org/user-guide/configuration/#hooks)\n[MkDocs 1.4 Release Notes](https://www.mkdocs.org/about/release-notes/#version-14-2022-09-27)\n[TechDocs Architecture](https://backstage.io/docs/features/techdocs/architecture)",
"id": "GHSA-6jr7-99pf-8vgf",
"modified": "2026-02-02T20:19:58Z",
"published": "2026-02-02T20:19:58Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/backstage/backstage/security/advisories/GHSA-6jr7-99pf-8vgf"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-25153"
},
{
"type": "PACKAGE",
"url": "https://github.com/backstage/backstage"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L",
"type": "CVSS_V3"
}
],
"summary": "@backstage/plugin-techdocs-node vulnerable to arbitrary code execution via MkDocs hooks"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.