{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "MISP",
          "programFiles": [
            "app/Lib/Tools/EventGraphTool.php"
          ],
          "repo": "https://github.com/MISP/MISP",
          "vendor": "MISP",
          "versions": [
            {
              "lessThanOrEqual": "2.5.45",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Scottish Government - National Cyber Team"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "iglocska"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Claude Opus 5 (1M context)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eAffected versions of MISP allow authenticated users to retrieve object-reference records by UUID through \u003ccode\u003eEventGraphTool::get_reference_data()\u003c/code\u003e without first checking whether the requester is authorized to view the object the reference belongs to.\u003c/p\u003e\n\u003cp\u003eThe vulnerable code queried \u003ccode\u003eObjectReference.uuid\u003c/code\u003e directly and returned the matching row whenever it existed. Because no parent-object ACL was applied, a user who knew or obtained a reference UUID could retrieve information associated with an object outside their normal access scope. The commit explicitly states that \u003cstrong\u003eany object reference could be returned by UUID without authorizing its parent object\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eThe fix retrieves the referenced object\u0027s \u003ccode\u003eobject_id\u003c/code\u003e and calls \u003ccode\u003efetchObjectSimple()\u003c/code\u003e with the current user. If the user cannot access that parent object, MISP now returns \u003ccode\u003eNotFoundException\u003c/code\u003e instead of exposing the reference.\u003c/p\u003eVersion affected: \u22642.5.45\u003cbr\u003e"
            }
          ],
          "value": "Affected versions of MISP allow authenticated users to retrieve object-reference records by UUID through EventGraphTool::get_reference_data() without first checking whether the requester is authorized to view the object the reference belongs to.\n\n\nThe vulnerable code queried ObjectReference.uuid directly and returned the matching row whenever it existed. Because no parent-object ACL was applied, a user who knew or obtained a reference UUID could retrieve information associated with an object outside their normal access scope. The commit explicitly states that any object reference could be returned by UUID without authorizing its parent object.\n\n\nThe fix retrieves the referenced object\u0027s object_id and calls fetchObjectSimple() with the current user. If the user cannot access that parent object, MISP now returns NotFoundException instead of exposing the reference.\n\nVersion affected: \u22642.5.45"
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-1",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-639",
              "description": "CWE-639 Authorization Bypass Through User-Controlled Key",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-862",
              "description": "CWE-862 Missing Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "orgId": "00000000-0000-4000-9000-000000000000"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/MISP/MISP/commit/c0cb5c9f8"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "MISP Event Graph Object Reference Lookup Exposes References from Unauthorized Objects",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "00000000-0000-4000-9000-000000000000",
    "cveId": "CVE-2026-86451",
    "datePublished": "2026-09-07T12:59:35.971838Z",
    "dateReserved": "2026-09-07T12:59:41.676Z",
    "dateUpdated": "2026-09-07T12:59:41.744409Z",
    "requesterUserId": "00000000-0000-4000-9000-000000000000",
    "serial": 1,
    "state": "PUBLISHED",
    "vulnId": "gcve-1-2026-20223"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}