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TI-2026-69052 Aliases CVE-2026-106456GHSA-472h-9c5j-prrr

Inconsistent credential enforcement in Backstage proxy routes

Priority LOW 28CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · Low · 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-863.

Summary

The @backstage/plugin-proxy-backend package from 0.5.0 before 0.6.18 enforces credentials inconsistently for overlapping proxy routes (CWE-863). When a parent path allows unauthenticated access and a nested path requires credentials, the parent exemption can also cover requests handled by the nested proxy. An unauthenticated remote attacker can therefore reach the nested upstream through Backstage, including when static upstream credentials are configured for that proxy.

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 0.5.0 until 0.6.18, the @backstage/plugin-proxy-backend package is affected by inconsistent credential enforcement for overlapping proxy routes. An operator can configure overlapping proxy paths with different credential requirements. When a parent path permits unauthenticated access and a nested path requires credentials, the parent exemption can also cover requests handled by the nested proxy. An unauthenticated caller may therefore reach the nested upstream through Backstage, including with static upstream credentials configured for that proxy. This issue is fixed in version 0.6.18.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00239 15th percentileScored 2026-11-07
Fix Partial backstage (backstage): 1.55.0plugin-proxy-backend (@backstage): 0.6.18+1 more productRed Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
backstagebackstage1.28.0 to before 1.55.01.55.0Patch availableCNA
backstageplugin-proxy-backend0.5.0 to before 0.6.180.6.18Patch availableCNA
—@backstage/plugin-proxy-backend (npm)0.5.0 to before 0.6.180.6.18Patch availableGHSA-472h-9c5j-prrr
  • backstage Vendorbackstage Affected 1.28.0 to before 1.55.0 Fixed in 1.55.0 Patch available CNA
  • plugin-proxy-backend Vendorbackstage Affected 0.5.0 to before 0.6.18 Fixed in 0.6.18 Patch available CNA
  • @backstage/plugin-proxy-backend (npm) Vendor— Affected 0.5.0 to before 0.6.18 Fixed in 0.6.18 Patch available GHSA-472h-9c5j-prrr

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:linuxfoundation:backstage\/plugin-proxy-backend:*:*:*:*:*:node.js:*:*0.5.0 to before 0.6.18Vulnerablebackstage
cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*1.28.0 to before 1.55.0Vulnerablebackstage
  • cpe:2.3:a:linuxfoundation:backstage\/plugin-proxy-backend:*:*:*:*:*:node.js:*:* Versions 0.5.0 to before 0.6.18 Vulnerable ·backstage
  • cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:* Versions 1.28.0 to before 1.55.0 Vulnerable ·backstage

Remediation

Upgrade @backstage/plugin-proxy-backend to version 0.6.18, which fixes this issue. The sources list no fixed version for backstage. Red Hat rates this Moderate and lists Red Hat Developer Hub 1 and Self-service automation portal 2 as affected, with no plan available.

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-proxy-backend (@backstage) Fixed in 0.6.18
  • Fix · GHSA-472h-9c5j-prrr @backstage/plugin-proxy-backend (npm) Fixed in 0.6.18 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-2026-106456
  2. 2026-10-07 CISA SSVC decision points changed
  3. 2026-10-07 Alias added: GHSA-472h-9c5j-prrr
  4. 2026-10-07 Fix available: npm/@backstage/[email protected] · GHSA-472h-9c5j-prrr
  5. 2026-10-07 CVSS score added · GHSA-472h-9c5j-prrr
  6. 2026-10-07 Weakness changed · GHSA-472h-9c5j-prrr
  7. 2026-10-07 5 new references · GHSA-472h-9c5j-prrr
  8. 2026-10-08 Affected versions changed · Red Hat
  9. 2026-10-08 CVSS score added · Red Hat
  10. 2026-10-27 Affected versions changed · Red Hat
  11. 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