CVE-2026-24047 — @backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass
Backstage is an open framework for building developer portals, and @backstage/cli-common provides config loading functionality used by the backend and command line interface of …
Published: 2026-01-21 · CVSS: 6.3 · CVSS 3.1
Backstage is an open framework for building developer portals, and @backstage/cli-common provides config loading functionality used by the backend and command line interface of Backstage. Prior to version 0.1.17, the `resolveSafeChildPath` utility function in `@backstage/backend-plugin-api`, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation via symlink chains (creating `link1 → link2 → /outside` where intermediate symlinks eventually resolve outside the allowed directory) and dangling symlinks (creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations). This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories. This vulnerability is fixed in `@backstage/backend-plugin-api` version 0.1.17. Users should upgrade to this version or later. Some workarounds are available. Run Backstage in a containerized environment with limited filesystem access and/or restrict template creation to trusted users.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7