Vulnerability-Lookup

GHSA-H8FP-F39C-Q6MH

Vulnerability from github – Published: 2026-07-23 19:35 – Updated: 2026-07-23 19:35

Summary

React Router: RSCErrorHandler Missing Protocol Validation (XSS)

Details

This is a follow up to https://github.com/remix-run/react-router/security/advisories/GHSA-8646-j5j9-6r62. React Router was alerted of a code path in the (unstable) RSC error handling path in which redirects from untrusted sources could still result in an XSS vector via attacker-supplied redirect targets

[!NOTE] This only affects your application if you are using the unstable RSC APIs

Severity

6.9 (Medium)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "react-router"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.11.0"
            },
            {
              "fixed": "7.18.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-53667"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-23T19:35:57Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "This is a follow up to https://github.com/remix-run/react-router/security/advisories/GHSA-8646-j5j9-6r62.  React Router was alerted of a code path in the (unstable) RSC error handling path in which redirects from untrusted sources could still result in an XSS vector via attacker-supplied redirect targets\n\n\u003e [!NOTE]\n\u003e This only affects your application if you are using the unstable RSC APIs",
  "id": "GHSA-h8fp-f39c-q6mh",
  "modified": "2026-07-23T19:35:57Z",
  "published": "2026-07-23T19:35:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/remix-run/react-router/security/advisories/GHSA-h8fp-f39c-q6mh"
    },
    {
      "type": "WEB",
      "url": "https://github.com/remix-run/react-router/pull/15177"
    },
    {
      "type": "WEB",
      "url": "https://github.com/remix-run/react-router/commit/ce596e823f0d7b883a433af1d5a839a8b9fe0242"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/remix-run/react-router"
    },
    {
      "type": "WEB",
      "url": "https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180"
    },
    {
      "type": "WEB",
      "url": "https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "React Router: RSCErrorHandler Missing Protocol Validation (XSS)"
}

CVE-2026-53667 (GCVE-0-2026-53667)

Vulnerability from cvelistv5 – Published: 2026-07-27 21:21 – Updated: 2026-07-28 13:51

Title

React Router: Cross-site Scripting is Possible due to Missing RSCErrorHandler Protocol Validation (Incomplete fix for CVE-2026-53667)

Summary

React Router is a router for React. In versions 7.11.0 through 7.17.0, the RSCErrorHandler is missing protocol validation, allowing for redirects from untrusted sources. This issue is a follow up to CVE-2026-53667, and only affects consuming applications if they are using the unstable RSC APIs. This issue has been fixed in version 7.18.0.

Severity

6.9 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-28 13:51 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/remix-run/react-router/securit…	x_refsource_CONFIRM
https://github.com/remix-run/react-router/pull/15177	x_refsource_MISC
https://github.com/remix-run/react-router/commit/…	x_refsource_MISC
https://github.com/remix-run/react-router/blob/ma…	x_refsource_MISC
https://github.com/remix-run/react-router/release…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
remix-run	react-router	Affected: >= 7.11.0, < 7.18.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-53667",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-28T13:51:03.703369Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-28T13:51:15.333Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "react-router",
          "vendor": "remix-run",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 7.11.0, \u003c 7.18.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "React Router is a router for React. In versions 7.11.0 through 7.17.0, the RSCErrorHandler is missing protocol validation, allowing for redirects from untrusted sources. This issue is a follow up to CVE-2026-53667, and only affects consuming applications if they are using the unstable RSC APIs. This issue has been fixed in version 7.18.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-27T21:21:16.084Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/remix-run/react-router/security/advisories/GHSA-h8fp-f39c-q6mh",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/remix-run/react-router/security/advisories/GHSA-h8fp-f39c-q6mh"
        },
        {
          "name": "https://github.com/remix-run/react-router/pull/15177",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/remix-run/react-router/pull/15177"
        },
        {
          "name": "https://github.com/remix-run/react-router/commit/ce596e823f0d7b883a433af1d5a839a8b9fe0242",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/remix-run/react-router/commit/ce596e823f0d7b883a433af1d5a839a8b9fe0242"
        },
        {
          "name": "https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180"
        },
        {
          "name": "https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0"
        }
      ],
      "source": {
        "advisory": "GHSA-h8fp-f39c-q6mh",
        "discovery": "UNKNOWN"
      },
      "title": "React Router: Cross-site Scripting is Possible due to Missing RSCErrorHandler Protocol Validation (Incomplete fix for CVE-2026-53667)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-53667",
    "datePublished": "2026-07-27T21:21:16.084Z",
    "dateReserved": "2026-06-09T20:50:36.877Z",
    "dateUpdated": "2026-07-28T13:51:15.333Z",
    "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.

Detection rules are retrieved from Rulezet.

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.