FKIE_CVE-2026-3125

Vulnerability from fkie_nvd - Published: 2026-03-04 19:16 - Updated: 2026-03-09 17:51
Severity ?
6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Summary
A Server-Side Request Forgery (SSRF) vulnerability was identified in the @opennextjs/cloudflare package, resulting from a path normalization bypass in the /cdn-cgi/image/ handler.The @opennextjs/cloudflare worker template includes a /cdn-cgi/image/ handler intended for development use only. In production, Cloudflare's edge intercepts /cdn-cgi/image/ requests before they reach the Worker. However, by substituting a backslash for a forward slash (/cdn-cgi\image/ instead of /cdn-cgi/image/), an attacker can bypass edge interception and have the request reach the Worker directly. The JavaScript URL class then normalizes the backslash to a forward slash, causing the request to match the handler and trigger an unvalidated fetch of arbitrary remote URLs. For example: https://victim-site.com/cdn-cgi\image/aaaa/https://attacker.com In this example, attacker-controlled content from attacker.com is served through the victim site's domain (victim-site.com), violating the same-origin policy and potentially misleading users or other services. Note: This bypass only works via HTTP clients that preserve backslashes in paths (e.g., curl --path-as-is). Browsers normalize backslashes to forward slashes before sending requests. Additionally, Cloudflare Workers with Assets and Cloudflare Pages suffer from a similar vulnerability. Assets stored under /cdn-cgi/ paths are not publicly accessible under normal conditions. However, using the same backslash bypass (/cdn-cgi\... instead of /cdn-cgi/...), these assets become publicly accessible. This could be used to retrieve private data. For example, Open Next projects store incremental cache data under /cdn-cgi/_next_cache, which could be exposed via this bypass.
References
cna@cloudflare.comhttps://github.com/advisories/GHSA-rvpw-p7vw-wj3mThird Party Advisory
cna@cloudflare.comhttps://github.com/opennextjs/opennextjs-cloudflare/pull/1147Issue Tracking, Patch
cna@cloudflare.comhttps://www.cve.org/cverecord?id=CVE-2025-6087Third Party Advisory
cna@cloudflare.comhttps://www.npmjs.com/package/@opennextjs/cloudflare/v/1.17.1Product, Release Notes
Impacted products
Vendor Product Version
opennextjs opennext_for_cloudflare *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:opennextjs:opennext_for_cloudflare:*:*:*:*:*:node.js:*:*",
              "matchCriteriaId": "FFD587A5-A6DA-4D83-9903-7AD395DE5744",
              "versionEndExcluding": "1.17.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A Server-Side Request Forgery (SSRF) vulnerability was identified in the @opennextjs/cloudflare package, resulting from a path normalization bypass in the /cdn-cgi/image/ handler.The @opennextjs/cloudflare worker template includes a /cdn-cgi/image/ handler intended for development use only. In production, Cloudflare\u0027s edge intercepts /cdn-cgi/image/ requests before they reach the Worker. However, by substituting a backslash for a forward slash (/cdn-cgi\\image/ instead of /cdn-cgi/image/), an attacker can bypass edge interception and have the request reach the Worker directly. The JavaScript URL class then normalizes the backslash to a forward slash, causing the request to match the handler and trigger an unvalidated fetch of arbitrary remote URLs.\n\nFor example: \n\n https://victim-site.com/cdn-cgi\\image/aaaa/https://attacker.com \n\nIn this example, attacker-controlled content from attacker.com is served through the victim site\u0027s domain (victim-site.com), violating the same-origin policy and potentially misleading users or other services.\n\nNote: This bypass only works via HTTP clients that preserve backslashes in paths (e.g., curl --path-as-is). Browsers normalize backslashes to forward slashes before sending requests.\n\nAdditionally, Cloudflare Workers with Assets and Cloudflare Pages suffer from a similar vulnerability. Assets stored under /cdn-cgi/ paths are not publicly accessible under normal conditions. However, using the same backslash bypass (/cdn-cgi\\... instead of /cdn-cgi/...), these assets become publicly accessible. This could be used to retrieve private data. For example, Open Next projects store incremental cache data under /cdn-cgi/_next_cache, which could be exposed via this bypass."
    },
    {
      "lang": "es",
      "value": "Una vulnerabilidad de falsificaci\u00f3n de petici\u00f3n del lado del servidor (SSRF) fue identificada en el paquete @opennextjs/cloudflare, resultante de un bypass de normalizaci\u00f3n de ruta en el gestor /cdn-cgi/image/. La plantilla de worker @opennextjs/cloudflare incluye un gestor /cdn-cgi/image/ destinado solo para uso en desarrollo. En producci\u00f3n, el edge de Cloudflare intercepta las peticiones /cdn-cgi/image/ antes de que lleguen al Worker. Sin embargo, al sustituir una barra invertida por una barra inclinada (/cdn-cgi\\image/ en lugar de /cdn-cgi/image/), un atacante puede eludir la intercepci\u00f3n del edge y hacer que la petici\u00f3n llegue directamente al Worker. La clase URL de JavaScript luego normaliza la barra invertida a una barra inclinada, haciendo que la petici\u00f3n coincida con el gestor y desencadene una obtenci\u00f3n no validada de URLs remotas arbitrarias.\n\nPor ejemplo:\n\nhttps://victim-site.com/cdn-cgi\\image/aaaa/https://attacker.com\n\nEn este ejemplo, contenido controlado por el atacante de attacker.com se sirve a trav\u00e9s del dominio del sitio v\u00edctima (victim-site.com), violando la pol\u00edtica de mismo origen y potencialmente enga\u00f1ando a usuarios u otros servicios.\n\nNota: Este bypass solo funciona a trav\u00e9s de clientes HTTP que preservan las barras invertidas en las rutas (p. ej., curl --path-as-is). Los navegadores normalizan las barras invertidas a barras inclinadas antes de enviar las peticiones.\n\nAdem\u00e1s, Cloudflare Workers con Assets y Cloudflare Pages sufren de una vulnerabilidad similar. Los Assets almacenados bajo rutas /cdn-cgi/ no son accesibles p\u00fablicamente bajo condiciones normales. Sin embargo, utilizando el mismo bypass de barra invertida (/cdn-cgi\\... en lugar de /cdn-cgi/...), estos assets se vuelven accesibles p\u00fablicamente. Esto podr\u00eda usarse para recuperar datos privados. Por ejemplo, los proyectos Open Next almacenan datos de cach\u00e9 incremental bajo /cdn-cgi/_next_cache, que podr\u00edan ser expuestos a trav\u00e9s de este bypass."
    }
  ],
  "id": "CVE-2026-3125",
  "lastModified": "2026-03-09T17:51:18.853",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 2.5,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.7,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "HIGH",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "LOW",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "cna@cloudflare.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-03-04T19:16:19.730",
  "references": [
    {
      "source": "cna@cloudflare.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/advisories/GHSA-rvpw-p7vw-wj3m"
    },
    {
      "source": "cna@cloudflare.com",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "url": "https://github.com/opennextjs/opennextjs-cloudflare/pull/1147"
    },
    {
      "source": "cna@cloudflare.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.cve.org/cverecord?id=CVE-2025-6087"
    },
    {
      "source": "cna@cloudflare.com",
      "tags": [
        "Product",
        "Release Notes"
      ],
      "url": "https://www.npmjs.com/package/@opennextjs/cloudflare/v/1.17.1"
    }
  ],
  "sourceIdentifier": "cna@cloudflare.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-706"
        },
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "cna@cloudflare.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

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.