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 scaffolder action input authorization bypass. An authenticated user with access to affected Scaffolder templates could bypass configured action restrictions. Depending on integration credentials, this could grant unauthorized access to repositories and related source-control resources. This issue is fixed in versions 3.3.1, 3.4.1, 4.0.3 and 4.1.0.
CVE-2026-106503
HIGHPre-NVD 8.18.1
EchelonGraph scoreLOW confidence
This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 8.1Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 8.1
- EG Score
- 8.1HIGHlow confidence
- EG Risk
- 41EG Risk 41/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity81% × 45%Exploitation0% × 40%Automatability30% × 15%CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 6, 2026
Last Modified
October 7, 2026
Advisory Details (7)
Auto-updated Oct 6, 2026Patch available. Sources: github, github_commit, github_release.
github_release Patch Available
v1.54.6
Patch available: backstage/backstage v1.54.6
https://github.com/backstage/backstage/releases/tag/v1.54.6github_release Patch Available
v1.50.5
Patch available: backstage/backstage v1.50.5
https://github.com/backstage/backstage/releases/tag/v1.50.5github_release Patch Available
v1.49.6
Patch available: backstage/backstage v1.49.6
https://github.com/backstage/backstage/releases/tag/v1.49.6github_commit Patch Available
commit e307e4f48710 (backstage/backstage)
Patch available: backstage/backstage v1.50.5 (contains commit e307e4f48710)
https://github.com/backstage/backstage/commit/e307e4f487103d815e484291b3fda778ab9983bfgithub_commit Patch Available
commit a91ed72d540e (backstage/backstage)
Patch available: backstage/backstage v1.54.6 (contains commit a91ed72d540e)
https://github.com/backstage/backstage/commit/a91ed72d540e80b62a73b39bb1563ff5018d52d1github_commit Patch Available
commit 11c1384c0649 (backstage/backstage)
Patch available: backstage/backstage v1.49.6 (contains commit 11c1384c0649)
https://github.com/backstage/backstage/commit/11c1384c0649b8ab26391c6a4e4f34b80ab0d188githubMentions a patch (unverified)
Scaffolder action input authorization bypass · Advisory · backstage/backstage · GitHub
https://github.com/backstage/backstage/security/advisories/GHSA-hmp2-4m7g-22cvVendor Advisories for CVE-2026-106503(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| @backstage/plugin-scaffolder-backend | — |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 3× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-06 22:32 UTCEG score recompute
- 2026-10-06 21:47 UTCEG score recompute
- 2026-10-06 21:46 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(4)
What is CVE-2026-106503?
CVE-2026-106503 is a high vulnerability published on October 6, 2026. 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 scaffolder action input authorization bypass. An authenticated user with access to affected Scaffolder templates could bypass…
When was CVE-2026-106503 disclosed?
CVE-2026-106503 was first published on October 6, 2026, with the most recent update on October 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-106503?
CVE-2026-106503 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-106503?
A fix for CVE-2026-106503 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-106503 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-106503
Is Your Infrastructure Affected by CVE-2026-106503?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.