{"id":"CVE-2026-54566","summary":"Markdown Preview Enhanced: Remote Code Execution via VM Sandbox Escape in `.crossnote/config.js` and `.crossnote/parser.js`","details":"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.","aliases":["GHSA-427h-jhpr-8jch"],"modified":"2026-10-16T02:47:46.734641158Z","published":"2026-10-14T19:08:43.663Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-94"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54566.json"},"references":[{"type":"WEB","url":"https://github.com/shd101wyy/crossnote/releases/tag/0.9.30"},{"type":"WEB","url":"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.29"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54566.json"},{"type":"ADVISORY","url":"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54566"},{"type":"FIX","url":"https://github.com/shd101wyy/crossnote/commit/e4890d64502e53b717cce0cb73f1a78b244dc640"},{"type":"FIX","url":"https://github.com/shd101wyy/crossnote/pull/443"},{"type":"FIX","url":"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/0d4010988c6ae56a38c6dec4a7509cbd5a7dcb4c"},{"type":"FIX","url":"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2320"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/shd101wyy/crossnote","events":[{"introduced":"0"},{"fixed":"e4890d64502e53b717cce0cb73f1a78b244dc640"}],"database_specific":{"source":"REFERENCES"}},{"type":"GIT","repo":"https://github.com/shd101wyy/vscode-markdown-preview-enhanced","events":[{"introduced":"0"},{"fixed":"0d4010988c6ae56a38c6dec4a7509cbd5a7dcb4c"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"0.8.29"}]}}],"versions":["0.9.29","0.9.28","0.9.27","0.9.26","0.9.25","0.9.24","0.9.23","0.9.22","0.9.21","0.9.20","0.9.19","0.9.18","0.9.17","0.9.16","0.9.15","0.9.14","0.9.13","0.9.12","0.9.11","0.9.10","0.9.9","0.9.8","0.9.7","0.9.6","0.9.5","0.9.4","0.9.3","0.9.2","0.9.1","0.9.0","0.8.24","0.8.23","0.8.22","0.8.21","0.8.20","0.8.19","0.8.18","0.8.17","0.8.16","0.8.15","0.8.14","0.8.13","0.8.28","0.8.27","0.8.26","0.8.25","0.8.12","0.8.11","0.8.10","0.8.9","0.8.8","0.8.7","0.8.6","0.8.5","0.8.4","0.8.3","0.8.2","0.8.1","0.8.0","0.7.10","0.7.9","0.7.8","0.7.7","v0.7.6","v0.7.5","v0.7.4","v0.7.3","v0.7.2","v0.7.1","v0.7.0","v0.6.10","v0.6.8","v0.6.7","v0.6.6","v0.6.5","v0.6.3","v0.6.2","v0.6.1","v0.6.0","v0.5.22","v0.5.21","v0.5.20","v0.5.18","v0.5.17","v0.5.16","v0.5.15","v0.5.14","v0.5.13","v0.5.12","v0.5.11","v0.5.10","v0.5.9","v0.5.8","v0.5.4","v0.5.3","v0.5.2","v0.5.1","0.5.1","0.5.0","v0.4.3","0.4.3","v0.4.2","0.4.2","v0.4.1","0.4.1","0.4.0","v0.3.13","0.3.13","v0.3.12","0.3.12","0.3.11","0.3.10","0.3.9","0.3.8","0.3.7","0.3.6","0.3.5","0.3.4","0.3.3","0.3.2","0.3.1","0.3.0","0.2.9","0.2.8","0.2.7","0.2.6","0.2.5","0.2.4","0.2.3","0.2.2","0.2.1","0.2.0","0.1.9","0.1.8","0.1.7","0.1.6","0.1.5","0.1.4","0.1.3","0.1.2","0.1.1","0.1.0","0.0.9","0.0.8"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54566.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}