# CVE-2026-24047: @backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass

> Attackers can bypass path validation via symlink chains to read or modify files outside allowed directories in Backstage backend components.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Jan 2026
- **Updated:** 22 Jan 2026
- **Also known as:** GHSA-2p49-45hj-7mc9

## What is CVE-2026-24047?

CVE-2026-24047 is a medium-severity path traversal vulnerability in backstage, published on 21 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-61 (UNIX Symbolic Link (Symlink) Following), CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-24047?

2 open source packages ship an affected version, including @backstage/cli-common.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@backstage/cli-common` | npm | All versions | 0.1.17 |
| `@backstage/cli-common` | npm | All versions | 0.1.17 |

## How do I fix CVE-2026-24047?

Upgrade @backstage/cli-common to 0.1.17 or later.

## Is CVE-2026-24047 being exploited?

There is no known exploitation of CVE-2026-24047 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-24047 and fix it if it is affected.

What it is: CVE-2026-24047 is a medium-severity path traversal vulnerability in backstage, published on 21 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-24047 in the wild and no public exploit code.

Affected packages and fixed versions:
- @backstage/cli-common (npm): affected all versions; fixed in 0.1.17
- @backstage/cli-common (npm): affected all versions; fixed in 0.1.17

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-24047/ (Markdown: https://insights.sbomify.com/CVE-2026-24047/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-24047
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-24047
- OSV: https://osv.dev/vulnerability/CVE-2026-24047

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-24047/
Summaries are generated and may contain mistakes; the official description above is the record.