{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "Kugelblitz with Microsoft"
        ]
      },
      {
        "names": [
          "Kugelblitz with Microsoft"
        ]
      }
    ],
    "aggregate_severity": {
      "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
      "text": "Important"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      },
      {
        "category": "general",
        "text": "Required. The vulnerability documented by this CVE requires customer action to resolve.",
        "title": "Customer Action"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-66312 Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66312"
      },
      {
        "category": "self",
        "summary": "CVE-2026-66312 Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-66312.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Exploitability Index",
        "url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability",
    "tracking": {
      "current_release_date": "2026-07-31T07:00:00.000Z",
      "generator": {
        "date": "2026-08-03T22:52:39.415Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-66312",
      "initial_release_date": "2026-07-31T07:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-07-31T07:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "<151.0.4129.59",
            "product": {
              "name": "Microsoft Edge (Chromium-based) <151.0.4129.59",
              "product_id": "1"
            }
          },
          {
            "category": "product_version",
            "name": "151.0.4129.59",
            "product": {
              "name": "Microsoft Edge (Chromium-based) 151.0.4129.59",
              "product_id": "11655"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Edge (Chromium-based)"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-66312",
      "cwe": {
        "id": "CWE-126",
        "name": "Buffer Over-read"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "151.0.4129.59: 151.0.4129.59, 07/31/2026: 07/31/2026, 151.0.7922.71/.72: 151.0.7922.71/.72",
          "title": "What is the version information for this release?"
        },
        {
          "category": "faq",
          "text": "Any authenticated attacker could trigger this vulnerability. It does not require admin or other elevated privileges.",
          "title": "According to the CVSS metric, privileges required is low (PR:L).  What does that mean for this vulnerability?"
        }
      ],
      "product_status": {
        "fixed": [
          "11655"
        ],
        "known_affected": [
          "1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-66312 Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66312"
        },
        {
          "category": "self",
          "summary": "CVE-2026-66312 Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-66312.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-07-31T07:00:00.000Z",
          "details": "151.0.4129.59:Security Update:https://docs.microsoft.com/en-us/DeployEdge/microsoft-edge-relnotes-security",
          "product_ids": [
            "1"
          ],
          "url": "https://docs.microsoft.com/en-us/DeployEdge/microsoft-edge-relnotes-security"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "environmentalScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 5.7,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Remote Code Execution"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Unlikely"
        }
      ],
      "title": "Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability"
    }
  ]
}