{
  "containers": {
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      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "ADJACENT_NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 6.8,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-14440",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-02T19:22:08.681269Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-693",
                "description": "CWE-693 Protection Mechanism Failure",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-02T19:22:18.404Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "technical-description",
              "exploit"
            ],
            "url": "https://david-osipov.vision/en/blog/cybersecurity/cloudflare-ssl-mitm-flaw-2026/"
          },
          {
            "tags": [
              "related"
            ],
            "url": "https://community.cloudflare.com/t/critical-security-gap-cloudflare-must-fully-support-rfc-8657-caa/799999/10"
          },
          {
            "tags": [
              "related"
            ],
            "url": "https://community.cloudflare.com/t/universal-ssl-exposes-domains-to-bgp-leaks-re-venezuela-analysis/879930"
          },
          {
            "tags": [
              "technical-description",
              "exploit"
            ],
            "url": "https://zenodo.org/records/18330221"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "Cloud Service"
          ],
          "product": "Universal SSL",
          "vendor": "Cloudflare",
          "versions": [
            {
              "lessThanOrEqual": "current",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "David Osipov (ORCID: https://orcid.org/0009-0005-2713-9242), independent researcher"
        }
      ],
      "descriptions": [
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          "lang": "en",
          "supportingMedia": [
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              "value": "\u003cp\u003e\u003cb\u003eDescription:\u003c/b\u003e\u003c/p\u003e\u003cbr\u003e\u003cp\u003eTo issue and renew TLS certificates on behalf of customers, Cloudflare\u0027s Universal SSL feature automatically manages the CAA RRset for the customer\u0027s zone. This auto-managed RRset is permissive by design (e.g. \u0027issue \"letsencrypt.org\"\u0027 without parameters). On Universal SSL zones, Cloudflare\u0027s authoritative DNS serves this auto-managed RRset at query time, superseding any customer-configured CAA records on the zone. When a customer publishes a stricter CAA record using the RFC 8657 accounturi or validationmethods parameters, the Certificate Authority does not observe those parameters when evaluating the served RRset under RFC 8659. As a result, the RFC 8657 account-binding and validation-method-binding protections are not enforced end-to-end on Universal SSL zones. Successful exploitation could result in issuance of a browser-trusted TLS certificate to an attacker, enabling MITM against the affected domain.\u003c/p\u003e\u003cbr\u003e\u003cp\u003eExploitation is non-trivial in practice: an attacker would need to hold an ACME account at one of the Certificate Authorities in the served CAA RRset and to simultaneously satisfy domain control validation across the multiple geographically distinct Network Perspectives the CA relies on for Multi-Perspective Issuance Corroboration. Cloudflare prefixes are anycast-announced from hundreds of locations globally, raising the bar against single-vantage-point BGP hijacks. Any resulting misissuance of a browser-trusted certificate is subject to Certificate Transparency logging required by major browsers, and would be visible to CT monitoring.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\u003cp\u003e\u003cspan\u003e\u003cb\u003eMitigation:\u0026nbsp;\u003c/b\u003e\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan\u003eCustomers requiring strict RFC 8657 enforcement need to disable Universal SSL on the affected zone.\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan\u003eUniversal SSL\u0027s automatic CAA management and customer-set RFC 8657 accounturi and validationmethods enforcement are mutually exclusive by the nature of the issue, so there is no in-product workaround that preserves both.\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan\u003eCertificate Transparency monitoring is recommended for all customers as a general detection control.\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003e\u003c/b\u003e\u003cbr\u003e\u003c/p\u003e\u003cp\u003e\u003cspan\u003e\u003cb\u003eCredits:\u003c/b\u003e\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cspan\u003eDavid Osipov (ORCID: https://orcid.org/0009-0005-2713-9242), independent researcher\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003e\u003c/b\u003e\u003cbr\u003e\u003c/p\u003e\u003cbr\u003e"
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          "value": "Description:\n\n\n\n\nTo issue and renew TLS certificates on behalf of customers, Cloudflare\u0027s Universal SSL feature automatically manages the CAA RRset for the customer\u0027s zone. This auto-managed RRset is permissive by design (e.g. \u0027issue \"letsencrypt.org\"\u0027 without parameters). On Universal SSL zones, Cloudflare\u0027s authoritative DNS serves this auto-managed RRset at query time, superseding any customer-configured CAA records on the zone. When a customer publishes a stricter CAA record using the RFC 8657 accounturi or validationmethods parameters, the Certificate Authority does not observe those parameters when evaluating the served RRset under RFC 8659. As a result, the RFC 8657 account-binding and validation-method-binding protections are not enforced end-to-end on Universal SSL zones. Successful exploitation could result in issuance of a browser-trusted TLS certificate to an attacker, enabling MITM against the affected domain.\n\n\n\n\nExploitation is non-trivial in practice: an attacker would need to hold an ACME account at one of the Certificate Authorities in the served CAA RRset and to simultaneously satisfy domain control validation across the multiple geographically distinct Network Perspectives the CA relies on for Multi-Perspective Issuance Corroboration. Cloudflare prefixes are anycast-announced from hundreds of locations globally, raising the bar against single-vantage-point BGP hijacks. Any resulting misissuance of a browser-trusted certificate is subject to Certificate Transparency logging required by major browsers, and would be visible to CT monitoring.\n\n\n\n\n\n\n\n\nMitigation:\u00a0\n\n\n\nCustomers requiring strict RFC 8657 enforcement need to disable Universal SSL on the affected zone.\n\n\n\nUniversal SSL\u0027s automatic CAA management and customer-set RFC 8657 accounturi and validationmethods enforcement are mutually exclusive by the nature of the issue, so there is no in-product workaround that preserves both.\u00a0\n\n\n\nCertificate Transparency monitoring is recommended for all customers as a general detection control.\n\n\n\n\n\n\n\n\nCredits:\n\n\n\nDavid Osipov (ORCID: https://orcid.org/0009-0005-2713-9242), independent researcher"
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "ADJACENT",
            "baseScore": 7.6,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
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      "providerMetadata": {
        "dateUpdated": "2026-07-01T22:35:10.353Z",
        "orgId": "a22f1246-ba21-4bb4-a601-ad51614c1513",
        "shortName": "cloudflare"
      },
      "references": [
        {
          "url": "https://developers.cloudflare.com/ssl/edge-certificates/caa-records/"
        },
        {
          "url": "https://developers.cloudflare.com/ssl/edge-certificates/universal-ssl/limitations/"
        },
        {
          "url": "https://www.rfc-editor.org/rfc/rfc8657"
        },
        {
          "url": "https://www.rfc-editor.org/rfc/rfc8659"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "supportingMedia": [
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              "type": "text/html",
              "value": "\u003cb\u003e\u003cp\u003eCustomers requiring strict RFC 8657 enforcement need to disable Universal SSL on the affected zone.\u003c/p\u003e\u003cp\u003eUniversal SSL\u0027s automatic CAA management and customer-set RFC 8657 accounturi and validationmethods enforcement are mutually exclusive by the nature of the issue, so there is no in-product workaround that preserves both.\u0026nbsp;\u003c/p\u003e\u003cp\u003eCertificate Transparency monitoring is recommended for all customers as a general detection control.\u003c/p\u003e\u003c/b\u003e\u003cbr\u003e"
            }
          ],
          "value": "Customers requiring strict RFC 8657 enforcement need to disable Universal SSL on the affected zone.\n\n\n\nUniversal SSL\u0027s automatic CAA management and customer-set RFC 8657 accounturi and validationmethods enforcement are mutually exclusive by the nature of the issue, so there is no in-product workaround that preserves both.\u00a0\n\n\n\nCertificate Transparency monitoring is recommended for all customers as a general detection control."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Cloudflare Universal SSL automatically managed CAA RRset supersedes customer-configured CAA records",
      "x_generator": {
        "engine": "Vulnogram 1.0.2"
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  "cveMetadata": {
    "assignerOrgId": "a22f1246-ba21-4bb4-a601-ad51614c1513",
    "assignerShortName": "cloudflare",
    "cveId": "CVE-2026-14440",
    "datePublished": "2026-07-01T22:35:10.353Z",
    "dateReserved": "2026-07-01T22:20:45.895Z",
    "dateUpdated": "2026-07-02T19:22:18.404Z",
    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}