CVE-2026-24046

Symlink Slide: Escaping the Backstage Scaffolder Jail

Alon Barad
Alon Barad
Software Engineer

Jan 22, 2026·6 min read·15 visits

Executive Summary (TL;DR)

The Backstage Scaffolder didn't verify if symbolic links pointed outside the workspace before following them. An attacker can create a template that links to `/etc/passwd` (or other secrets), and use the `debug:log` action to print the contents of that file to the logs. It's a classic symlink race condition turned into a reliable jailbreak.

A high-severity path traversal vulnerability in Spotify's Backstage Scaffolder allows attackers to escape the workspace sandbox using symbolic links. By crafting malicious templates, attackers can read sensitive files, delete arbitrary data, or write outside the intended directory.

Fix Analysis (1)

Technical Appendix

CVSS Score
7.1/ 10
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L

Affected Systems

Backstage Developer PortalScaffolder Backend PluginNode.js environments running vulnerable Backstage versions

Affected Versions Detail

Product
Affected Versions
Fixed Version
@backstage/backend-defaults
Spotify/Backstage
< 0.12.20.12.2
@backstage/plugin-scaffolder-backend
Spotify/Backstage
3.0.0 - 3.0.13.0.2
@backstage/plugin-scaffolder-node
Spotify/Backstage
< 0.11.20.11.2
AttributeDetail
CVE IDCVE-2026-24046
CVSS v3.17.1 (High)
CWEsCWE-22, CWE-59
VectorAV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L
Attack VectorSymlink Path Traversal
ImpactArbitrary File Read/Write/Delete
CWE-22
Path Traversal

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') leading to access of files outside the intended scope via symbolic links.

Vulnerability Timeline

Fix commit authored by Ben Lambert
2026-01-20
Public Disclosure & GHSA Published
2026-01-21