---
title: "CVE-2026-106501: Backstage: Sensitive information exposure in Scaffolder"
url: https://erroneo.us/security/cve/CVE-2026-106501/
description: "CVE-2026-106501 (@backstage/plugin-scaffolder-backend (npm)): Backstage is an open framework for building developer portals. Prior to 3.3.1, 3.4.1, 4.0.3…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-10-06
date_modified: 2026-10-07
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-106501"
kev: false
cvss: 9.6
epss: 0.00483
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-106501: Backstage: Sensitive information exposure in Scaffolder

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.5% , percentile 41: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 41% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes @backstage/plugin-scaffolder-backend (npm) < 3.3.1, fixed in 3.3.1 ; @backstage/plugin-scaffolder-backend (npm) >= 3.4.0, < 3.4.1, fixed in 3.4.1 ; @backstage/plugin-scaffolder-backend (npm) >= 4.0.0, < 4.0.3, fixed in 4.0.3 ; @backstage/plugin-scaffolder-backend (npm) >= 4.0.4, < 4.1.0, fixed in 4.1.0 . Check your lockfile, including transitive dependencies.

## What it is

Backstage is an open framework for building developer portals. Prior to 3.3.1, 3.4.1, 4.0.3 and 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by sensitive information exposure in scaffolder. An authenticated Backstage user who can read another user's Scaffolder task may receive internal execution data. In deployments where that data contains credentials for an external service, this may permit disclosure and unauthorized changes in that external service. This issue is fixed in versions 3.3.1, 3.4.1, 4.0.3 and 4.1.0.

## Affected packages

- npm `@backstage/plugin-scaffolder-backend` < 3.3.1 → fixed: 3.3.1
- npm `@backstage/plugin-scaffolder-backend` >= 3.4.0, < 3.4.1 → fixed: 3.4.1
- npm `@backstage/plugin-scaffolder-backend` >= 4.0.0, < 4.0.3 → fixed: 4.0.3
- npm `@backstage/plugin-scaffolder-backend` >= 4.0.4, < 4.1.0 → fixed: 4.1.0

## Affected products (CVE record)

- backstage backstage: < 1.49.6, >= 1.50.0-next.0, < 1.50.5, >= 1.51.0-next.0, < 1.54.6
- @backstage plugin-scaffolder-backend: < 3.3.1, >= 3.4.0, < 3.4.1, >= 4.0.0, < 4.0.3, >= 4.0.4, < 4.1.0

## Severity

- GitHub_M CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.48% probability of exploitation activity in the next 30 days; percentile 41.

## Sources

- [GitHub Advisory GHSA-g2v8-7jhw-pp8p](https://github.com/advisories/GHSA-g2v8-7jhw-pp8p)
- [CVE.org record CVE-2026-106501](https://www.cve.org/CVERecord?id=CVE-2026-106501)
- [NVD entry CVE-2026-106501](https://nvd.nist.gov/vuln/detail/CVE-2026-106501)
- [github.com](https://github.com/backstage/backstage/security/advisories/GHSA-g2v8-7jhw-pp8p)
- [github.com](https://github.com/backstage/backstage/commit/66d2219edf0abe33ab7d0c1ced5d069d1e065be5)
- [github.com](https://github.com/backstage/backstage/commit/c19838870476a8e29144c84b1a5ac0654ec20fb5)
- [github.com](https://github.com/backstage/backstage/commit/e262d649981ff99bb01ca7077807ae3e25e85560)
- [github.com](https://github.com/backstage/backstage/releases/tag/v1.49.6)
- [github.com](https://github.com/backstage/backstage/releases/tag/v1.50.5)
- [github.com](https://github.com/backstage/backstage/releases/tag/v1.54.6)

---
Source page: https://erroneo.us/security/cve/CVE-2026-106501/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt