Vulnerability-Lookup

CVE-2026-55685 (GCVE-0-2026-55685)

Vulnerability from cvelistv5 – Published: 2026-07-27 21:45 – Updated: 2026-07-28 13:40

Title

React Router: Unauthenticated Denial of Service via Inefficient Route Matching

Summary

React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow up to CVE-2026-42342, and does not does not impact React Router applications using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>). This issue has been fixed in version 7.18.0.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-400 - Uncontrolled Resource Consumption
CWE-407 - Inefficient Algorithmic Complexity

Assigner

GitHub_M

References

6 references

URL	Tags
https://github.com/remix-run/react-router/securit…	x_refsource_CONFIRM
https://github.com/remix-run/react-router/securit…	x_refsource_MISC
https://github.com/remix-run/react-router/pull/15186	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: >= 7.0.0, < 7.18.0

Show details on NVD website

JSON

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                "id": "CVE-2026-55685",
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    "redhat_vex": {
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      "product_status:known_affected": "64",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "react-router: @remix-run/server-runtime: React Router: Denial of Service via unauthenticated manifest endpoint requests",
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}

GHSA-CHX6-HX7R-MCP5

Vulnerability from github – Published: 2026-07-24 14:06 – Updated: 2026-07-24 14:06

Summary

React Router: Unauthenticated Denial of Service via Inefficient Route Matching

Details

This is a follow up to https://github.com/remix-run/react-router/security/advisories/GHSA-8x6r-g9mw-2r78 that covers additional reported scenarios in which the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times.

[!NOTE] This only impacts Framework Mode applications. This does not impact your application if you are using Declarative or Data Mode.

Severity

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "react-router"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.18.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55685"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400",
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T14:06:57Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "This is a follow up to https://github.com/remix-run/react-router/security/advisories/GHSA-8x6r-g9mw-2r78 that covers additional reported scenarios in which the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times.\n\n\u003e [!NOTE]\n\u003e This only impacts Framework Mode applications.  This does not impact your application if you are using Declarative or Data Mode.",
  "id": "GHSA-chx6-hx7r-mcp5",
  "modified": "2026-07-24T14:06:57Z",
  "published": "2026-07-24T14:06:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/remix-run/react-router/security/advisories/GHSA-chx6-hx7r-mcp5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/remix-run/react-router/pull/15186"
    },
    {
      "type": "WEB",
      "url": "https://github.com/remix-run/react-router/commit/09e6020d1950e54f361f7ad00938ecd4dde60929"
    },
    {
      "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:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "React Router: Unauthenticated Denial of Service via Inefficient Route Matching"
}

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.

Action not permitted

CVE-2026-55685 (GCVE-0-2026-55685)

GHSA-CHX6-HX7R-MCP5

Tags

Sightings

Nomenclature