Vulnerability-Lookup

GHSA-826H-28H9-65HG

Vulnerability from github – Published: 2026-10-07 18:01 – Updated: 2026-10-07 18:01

Summary

Backstage: Improper authentication in the OIDC provider

Details

Impact

Deployments using OIDC email-based identity resolution with a provider that permits unverified email addresses may allow an authenticated provider user to assume another catalog identity. This may grant access and permissions associated with that user. No direct availability impact is demonstrated.

Patches

Patched in @backstage/plugin-auth-backend-module-oidc-provider version 0.4.20.

Workarounds

Disable email-based sign-in resolution for the OIDC provider, or require the identity provider to verify email addresses before allowing sign-in.

Severity

8.1 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@backstage/plugin-auth-backend-module-oidc-provider"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.4.20"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-106488"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-07T18:01:02Z",
    "nvd_published_at": "2026-10-06T21:17:17Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nDeployments using OIDC email-based identity resolution with a provider that permits unverified email addresses may allow an authenticated provider user to assume another catalog identity. This may grant access and permissions associated with that user. No direct availability impact is demonstrated.\n\n### Patches\n\nPatched in `@backstage/plugin-auth-backend-module-oidc-provider` version `0.4.20`.\n\n### Workarounds\n\n- Disable email-based sign-in resolution for the OIDC provider, or require the identity provider to verify email addresses before allowing sign-in.",
  "id": "GHSA-826h-28h9-65hg",
  "modified": "2026-10-07T18:01:02Z",
  "published": "2026-10-07T18:01:02Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/security/advisories/GHSA-826h-28h9-65hg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-106488"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/commit/1b1f05e82161aaabc226c1d7d498d746956bf942"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/backstage/backstage"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/releases/tag/v1.54.6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Backstage: Improper authentication in the OIDC provider"
}

CVE-2026-106488 (GCVE-0-2026-106488)

Vulnerability from cvelistv5 – Published: 2026-10-06 20:38 – Updated: 2026-10-07 18:23

Title

Backstage: Improper authentication in the OIDC provider

Summary

Backstage is an open framework for building developer portals. Prior to 0.4.20, the @backstage/plugin-auth-backend-module-oidc-provider package is affected by improper authentication in the oidc provider. Deployments using OIDC email-based identity resolution with a provider that permits unverified email addresses may allow an authenticated provider user to assume another catalog identity. This may grant access and permissions associated with that user. No direct availability impact is demonstrated. This issue is fixed in version 0.4.20.

Severity

8.1 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-07 18:23 UTC

CWE

CWE-287 - Improper Authentication

Assigner

GitHub_M mitre root Scorecard

References

3 references

URL	Tags
https://github.com/backstage/backstage/security/a…	x_refsource_CONFIRM
https://github.com/backstage/backstage/commit/1b1…	x_refsource_MISC
https://github.com/backstage/backstage/releases/t…	x_refsource_MISC

Impacted products

2 products

Vendor	Product	Version
backstage	backstage	Affected: < 1.54.6
@backstage	plugin-auth-backend-module-oidc-provider	Affected: < 0.4.20

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-106488",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-07T18:23:07.990382Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-07T18:23:28.366Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "backstage",
          "vendor": "backstage",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.54.6"
            }
          ]
        },
        {
          "product": "plugin-auth-backend-module-oidc-provider",
          "vendor": "@backstage",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.4.20"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Backstage is an open framework for building developer portals. Prior to 0.4.20, the @backstage/plugin-auth-backend-module-oidc-provider package is affected by improper authentication in the oidc provider. Deployments using OIDC email-based identity resolution with a provider that permits unverified email addresses may allow an authenticated provider user to assume another catalog identity. This may grant access and permissions associated with that user. No direct availability impact is demonstrated. This issue is fixed in version 0.4.20."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-287",
              "description": "CWE-287: Improper Authentication",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-06T20:38:18.045Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/backstage/backstage/security/advisories/GHSA-826h-28h9-65hg",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/backstage/backstage/security/advisories/GHSA-826h-28h9-65hg"
        },
        {
          "name": "https://github.com/backstage/backstage/commit/1b1f05e82161aaabc226c1d7d498d746956bf942",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/commit/1b1f05e82161aaabc226c1d7d498d746956bf942"
        },
        {
          "name": "https://github.com/backstage/backstage/releases/tag/v1.54.6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/releases/tag/v1.54.6"
        }
      ],
      "source": {
        "advisory": "GHSA-826h-28h9-65hg",
        "discovery": "UNKNOWN"
      },
      "title": "Backstage: Improper authentication in the OIDC provider"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-106488",
    "datePublished": "2026-10-06T20:38:18.045Z",
    "dateReserved": "2026-10-06T18:46:47.766Z",
    "dateUpdated": "2026-10-07T18:23:28.366Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted