Read the docs
TI-2026-69053 Aliases CVE-2026-106457GHSA-q333-f498-w2x7

Improper authentication in Backstage Cloudflare Access auth provider

Priority LOW 37CWE-287Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
Partial Red Hat: 2 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-287.

Summary

Backstage, from 1.26.0 before 1.55.0, and the @backstage/plugin-auth-backend-module-cloudflare-access-provider npm package, from 0.1.0 before 0.5.0, are affected. The Cloudflare Access auth provider checks the token signature and team issuer but not that the token was issued for the Backstage application (CWE-287). A user holding a valid token for another Access application in the same Cloudflare Zero Trust team may be able to authenticate to Backstage if that token reaches the auth endpoint without the Backstage application's audience already enforced upstream.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

Backstage is an open framework for building developer portals. From 0.1.0 until 0.5.0, the @backstage/plugin-auth-backend-module-cloudflare-access-provider package is affected by insufficient audience validation in the cloudflare access auth provider. The Cloudflare Access auth provider verifies a token's signature and team issuer, but affected versions do not verify that the token was issued for the Backstage application. A user holding a valid token for another Access application in the same Cloudflare Zero Trust team may therefore be able to authenticate to Backstage if that token reaches the auth endpoint without the Backstage application's audience already being enforced upstream. Cloudflare Access normally evaluates the protected application before forwarding requests. This issue is fixed in version 0.5.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00354 29th percentileScored 2026-11-07
Fix Partial backstage (backstage): 1.55.0plugin-auth-backend-module-cloudflare-access-provider (@backstage): 0.5.0+1 more productRed Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
backstagebackstage1.26.0 to before 1.55.01.55.0Patch availableCNA
backstageplugin-auth-backend-module-cloudflare-access-provider0.1.0 to before 0.5.00.5.0Patch availableCNA
—@backstage/plugin-auth-backend-module-cloudflare-access-provider (npm)0.1.0 to before 0.5.00.5.0Patch availableGHSA-q333-f498-w2x7
  • backstage Vendorbackstage Affected 1.26.0 to before 1.55.0 Fixed in 1.55.0 Patch available CNA
  • plugin-auth-backend-module-cloudflare-access-provider Vendorbackstage Affected 0.1.0 to before 0.5.0 Fixed in 0.5.0 Patch available CNA
  • @backstage/plugin-auth-backend-module-cloudflare-access-provider (npm) Vendor— Affected 0.1.0 to before 0.5.0 Fixed in 0.5.0 Patch available GHSA-q333-f498-w2x7

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:linuxfoundation:backstage\/plugin-auth-backend-module-cloudflare-access-provider:*:*:*:*:*:node.js:*:*0.1.0 to before 0.5.0Vulnerablebackstage
cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*1.26.0 to before 1.55.0Vulnerablebackstage
  • cpe:2.3:a:linuxfoundation:backstage\/plugin-auth-backend-module-cloudflare-access-provider:*:*:*:*:*:node.js:*:* Versions 0.1.0 to before 0.5.0 Vulnerable ·backstage
  • cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:* Versions 1.26.0 to before 1.55.0 Vulnerable ·backstage

Remediation

Update the @backstage/plugin-auth-backend-module-cloudflare-access-provider npm package to version 0.5.0. The sources list no fixed version for Backstage. Red Hat lists no available plan for Red Hat Developer Hub 1 and Self-service automation portal 2.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA backstage (backstage) Fixed in 1.55.0
  • Fix · CNA plugin-auth-backend-module-cloudflare-access-provider (@backstage) Fixed in 0.5.0
  • Fix · GHSA-q333-f498-w2x7 @backstage/plugin-auth-backend-module-cloudflare-access-provider (npm) Fixed in 0.5.0 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Developer Hub 1AffectedNo fix yet: Fix deferred
Self-service automation portal 2AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-07 Threatist record created from CVE-2026-106457
  2. 2026-10-07 CISA SSVC decision points changed
  3. 2026-10-07 Priority changed: MEDIUM → LOW
  4. 2026-10-07 Affected versions changed · Red Hat
  5. 2026-10-07 CVSS score added · Red Hat
  6. 2026-10-07 Alias added: GHSA-q333-f498-w2x7
  7. 2026-10-07 Fix available: npm/@backstage/[email protected] · GHSA-q333-f498-w2x7
  8. 2026-10-07 CVSS score added · GHSA-q333-f498-w2x7
  9. 2026-10-07 Weakness changed · GHSA-q333-f498-w2x7
  10. 2026-10-07 5 new references · GHSA-q333-f498-w2x7
  11. 2026-10-27 Affected versions changed · Red Hat
  12. 2026-10-27 CVSS score added · NVD

References

Patch 2

Advisory 2

Other 1

  • TI-2023-17988 Insecure sandbox in Backstage Scaffolder plugin CVSS 3.1CRITICAL 9.9
  • TI-2026-69075 Sensitive information exposure in Backstage Scaffolder CVSS 3.1CRITICAL 9.6
  • TI-2026-69061 Path traversal in Backstage Bitbucket pull-request scaffolder actions CVSS 3.1CRITICAL 9.9
  • TI-2026-60083 Backstage: Improper input validation in TechDocs MkDocs configuration CVSS 3.1HIGH 8.8
  • TI-2026-69165 Backstage TechDocs config flaw allows code execution CVSS 3.1HIGH 8.8
  • TI-2026-69083 Code injection via MkDocs theme configuration in Backstage TechDocs CVSS 3.1HIGH 8.8
See all 52 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences