Backstage has potential file exposure through local TechDocs publisher

### Impact When using the local TechDocs publisher (`techdocs.publisher.type: 'local'`), it was possible for the documentation serving endpoint to follow filesystem references outside the intended documentation tree, potentially exposing host files to authenticated users. This is mitigated by the fact that exploration requires preconditions that do not arise through normal MkDocs operation. Cloud-based publishers (S3, GCS, Azure Blob Storage) are not affected. ### Patches Patched in `@backstage/plugin-techdocs-node` version `1.15.4` ### Workarounds If you cannot upgrade immediately, consider switching to an external store for published TechDocs content (e.g. `awsS3`, `googleGcs`, or `azureBlobStorage` publishers)

Source published

7 Oct 2026 16:23:46 UTC

Source modified

7 Oct 2026 16:30:06 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Publisher rating · MODERATE