NVD / CVE Program· CNA GitHub_M

CVE-2026-24046: Backstage has a Possible Symlink Path Traversal in Scaffolder Actions

HighCVSS 7.1 · v3.1—Proof of concept Fix available

Noroxi assessment

Priority: Monitor (action score 28/100)

Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 0.52% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
Fixed version: @backstage/backend-defaults (npm) 0.13.2, 0.14.1, 0.12.2; @backstage/plugin-scaffolder-backend (npm) 3.0.2, 3.1.1, 2.2.2; @backstage/plugin-scaffolder-node (npm) 0.12.3, 0.11.2.

Low priority for now. Upgrade to @backstage/backend-defaults (npm) 0.13.2, 0.14.1, 0.12.2; @backstage/plugin-scaffolder-backend (npm) 3.0.2, 3.1.1, 2.2.2; @backstage/plugin-scaffolder-node (npm) 0.12.3, 0.11.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Backstage is an open framework for building developer portals. Multiple Scaffolder actions and archive extraction utilities were vulnerable to symlink-based path traversal attacks. An attacker with access to create and execute Scaffolder templates could exploit symlinks to read arbitrary files via the `debug:log` action by creating a symlink pointing to sensitive files (e.g., `/etc/passwd`, configuration files, secrets); delete arbitrary files via the `fs:delete` action by creating symlinks pointing outside the workspace, and write files outside the workspace via archive extraction (tar/zip) containing malicious symlinks. This affects any Backstage deployment where users can create or execute Scaffolder templates. This vulnerability is fixed in `@backstage/backend-defaults` versions 0.12.2, 0.13.2, 0.14.1, and 0.15.0; `@backstage/plugin-scaffolder-backend` versions 2.2.2, 3.0.2, and 3.1.1; and `@backstage/plugin-scaffolder-node` versions 0.11.2 and 0.12.3. Users should upgrade to these versions or later. Some workarounds are available. Follow the recommendation in the Backstage Threat Model to limit access to creating and updating templates, restrict who can create and execute Scaffolder templates using the permissions framework, audit existing templates for symlink usage, and/or run Backstage in a containerized environment with limited filesystem access.

Path traversal

GHSA-rq6q-wr2q-7pgp

Published: Jan 21, 2026
Updated: Jul 15, 2026
EPSS: 0.5% · 44th percentile
CWE: CWE-22

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 28 / 40 · 7.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.5%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 7.1; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Proof of concept exists, no weaponized module
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
rhdh	1.8	cpe:2.3:redhat:rhdh:1.8
rhdh	1.9	cpe:2.3:redhat:rhdh:1.9

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

backstage backstage
- @backstage/backend-defaults < 0.12.2, @backstage/backend-defaults >= 0.13.0, < 0.13.2, @backstage/backend-defaults >= 0.14.0, < 0.14.1, @backstage/plugin-scaffolder-backend < 2.2.2, @backstage/plugin-scaffolder-backend >= 3.0.0, < 3.0.2, @backstage/plugin-scaffolder-backend >= 3.1.0, < 3.1.1, @backstage/plugin-scaffolder-node < 0.11.2, @backstage/plugin-scaffolder-node >= 0.12.0, < 0.12.3affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
npm	@backstage/backend-defaults	from 0.13.0 · before 0.13.2	0.13.2
npm	@backstage/backend-defaults	from 0.14.0 · before 0.14.1	0.14.1
npm	@backstage/backend-defaults	before 0.12.2	0.12.2
npm	@backstage/plugin-scaffolder-backend	from 3.0.0 · before 3.0.2	3.0.2
npm	@backstage/plugin-scaffolder-backend	from 3.1.0 · before 3.1.1	3.1.1
npm	@backstage/plugin-scaffolder-backend	before 2.2.2	2.2.2
npm	@backstage/plugin-scaffolder-node	from 0.12.0 · before 0.12.3	0.12.3
npm	@backstage/plugin-scaffolder-node	before 0.11.2	0.11.2

Same product

backstage: all records

Other highest-scoring records for the same primary product.

CVE-2026-106557Backstage: Improper input validation in TechDocs Markdown extension configuration
30Monitor
CVE-2026-115923Backstage catalog rules can be bypassed for URL locations using encoded path segments
26Monitor
CVE-2026-24047@backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass
25Monitor

Published before and after this one in the same product

← EarlierCVE-2025-32791Apr 16, 2025 · Permission policy information leakage in Backstage permission system
17Monitor
← EarlierCVE-2025-55285Aug 15, 2025 · @backstage/plugin-scaffolder-backend Template Secret Leakage in Logs in Scaffolder When Using `fetch:template`
10Monitor
Later →CVE-2026-106495Oct 12, 2026 · Backstage: Improper access control in backend action invocation
17Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
npm:@backstage/backend-defaults	0.12.2	Package registry (OSV)
npm:@backstage/backend-defaults	0.13.2	Package registry (OSV)
npm:@backstage/backend-defaults	0.14.1	Package registry (OSV)
npm:@backstage/plugin-scaffolder-backend	2.2.2	Package registry (OSV)
npm:@backstage/plugin-scaffolder-backend	3.0.2	Package registry (OSV)
npm:@backstage/plugin-scaffolder-backend	3.1.1	Package registry (OSV)
npm:@backstage/plugin-scaffolder-node	0.11.2	Package registry (OSV)
npm:@backstage/plugin-scaffolder-node	0.12.3	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:0	2026-10-09

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedJan 21, 2026
First PoCOct 9, 2026+260 d
TodayNov 14, 2026+297 d

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

backstage/backstagecommit c641c14

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-106557259 days apartBackstage: Improper input validation in TechDocs Markdown extension configuration
30Monitor
CVE-2026-115923278 days apartBackstage catalog rules can be bypassed for URL locations using encoded path segments
26Monitor

Bug bounty scope

SpotifyHackerOne · paid · backstage/backstage

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Not on record for this CVE: EPSS history · researcher credit.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality: high · data can be read
Integrity: none
Availability: low · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector: Network
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: Changed
Confidentiality impact: High
Integrity impact: None
Availability impact: Low

Weakness class (CWE)

CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

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

nvd-secondary

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

The bug in code

The whole CWE-22 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1const file = path.join(ROOT, req.query.name);
2res.sendFile(file);

Fixed

1const file = path.resolve(ROOT, req.query.name);
2if (!file.startsWith(ROOT + path.sep)) {
3  return res.sendStatus(400);
4}
5res.sendFile(file);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log (2)

Exploit maturitynone → pocOct 10, 2026, 3:32 AM UTC
Fix✗ → ✓Sep 28, 2026, 10:47 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/backstage/backstage/commit/c641c147ab371a9a8a2f5f67fdb7cb9c97ef345d

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records

Noroxi analysis

What does it mean in your environment?

We use this product, ask for help

Data sources and verification

CNA: GitHub_M

CVE.org (CNA)Jul 15, 2026, 1:17 AM UTC
CISA ADPJul 15, 2026, 1:17 AM UTC
NVDJul 15, 2026, 1:17 AM UTC
FIRST EPSSNov 12, 2026, 12:00 AM UTC
OSV / GHSANov 13, 2026, 3:18 AM UTC
PoC-in-GitHubNov 13, 2026, 3:18 AM UTC

Each line is when that source was last processed for this record.