{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-54566",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-06-15T19:15:27.342Z",
        "datePublished": "2026-10-14T19:08:43.663Z",
        "dateUpdated": "2026-10-14T19:45:22.736Z"
    },
    "containers": {
        "cna": {
            "title": "Markdown Preview Enhanced: Remote Code Execution via VM Sandbox Escape in `.crossnote/config.js` and `.crossnote/parser.js`",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-94",
                            "lang": "en",
                            "description": "CWE-94: Improper Control of Generation of Code ('Code Injection')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "LOCAL",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "PASSIVE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "HIGH",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 8.5,
                        "baseSeverity": "HIGH",
                        "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch"
                },
                {
                    "name": "https://github.com/shd101wyy/crossnote/pull/443",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/shd101wyy/crossnote/pull/443"
                },
                {
                    "name": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2320",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2320"
                },
                {
                    "name": "https://github.com/shd101wyy/crossnote/commit/e4890d64502e53b717cce0cb73f1a78b244dc640",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/shd101wyy/crossnote/commit/e4890d64502e53b717cce0cb73f1a78b244dc640"
                },
                {
                    "name": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/0d4010988c6ae56a38c6dec4a7509cbd5a7dcb4c",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/0d4010988c6ae56a38c6dec4a7509cbd5a7dcb4c"
                },
                {
                    "name": "https://github.com/shd101wyy/crossnote/releases/tag/0.9.30",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/shd101wyy/crossnote/releases/tag/0.9.30"
                },
                {
                    "name": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.29",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.29"
                }
            ],
            "affected": [
                {
                    "vendor": "shd101wyy",
                    "product": "vscode-markdown-preview-enhanced",
                    "versions": [
                        {
                            "version": "< 0.8.29",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-10-14T19:08:43.663Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Markdown Preview Enhanced is a Markdown preview extension for Visual Studio Code. Prior to 0.8.29, Markdown Preview Enhanced evaluates repository-controlled .crossnote/config.js and .crossnote/parser.js files with vm.runInNewContext, which does not provide a security boundary from the Node.js host realm. Opening a Markdown file in a malicious repository automatically loads these files, and prototype-chain traversal can reach the host Function constructor and process object, allowing operating-system commands to execute as the victim account without further interaction. Both configuration evaluation and parser-hook evaluation are affected, and the attack does not depend on module-scoped require being available. This issue is fixed in version 0.8.29."
                }
            ],
            "source": {
                "advisory": "GHSA-427h-jhpr-8jch",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-10-14T19:44:50.050593Z",
                                "id": "CVE-2026-54566",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-10-14T19:45:22.736Z"
                }
            }
        ]
    }
}