CVE-2026-54566 (GCVE-0-2026-54566)
Vulnerability from cvelistv5
Published
2026-10-14 19:08
Modified
2026-10-14 19:45
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-94 - Improper Control of Generation of Code ('Code Injection')
Summary
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.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| shd101wyy | vscode-markdown-preview-enhanced |
Version: < 0.8.29 |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-54566",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-14T19:44:50.050593Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-14T19:45:22.736Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "vscode-markdown-preview-enhanced",
"vendor": "shd101wyy",
"versions": [
{
"status": "affected",
"version": "\u003c 0.8.29"
}
]
}
],
"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."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "LOCAL",
"baseScore": 8.5,
"baseSeverity": "HIGH",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "PASSIVE",
"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",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-94",
"description": "CWE-94: Improper Control of Generation of Code (\u0027Code Injection\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-14T19:08:43.663Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"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"
}
],
"source": {
"advisory": "GHSA-427h-jhpr-8jch",
"discovery": "UNKNOWN"
},
"title": "Markdown Preview Enhanced: Remote Code Execution via VM Sandbox Escape in `.crossnote/config.js` and `.crossnote/parser.js`"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-54566",
"datePublished": "2026-10-14T19:08:43.663Z",
"dateReserved": "2026-06-15T19:15:27.342Z",
"dateUpdated": "2026-10-14T19:45:22.736Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-54566\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-14T19:44:50.050593Z\"}}}], \"references\": [{\"url\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-14T19:45:05.683Z\"}}], \"cna\": {\"title\": \"Markdown Preview Enhanced: Remote Code Execution via VM Sandbox Escape in `.crossnote/config.js` and `.crossnote/parser.js`\", \"source\": {\"advisory\": \"GHSA-427h-jhpr-8jch\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 8.5, \"attackVector\": \"LOCAL\", \"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\", \"userInteraction\": \"PASSIVE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"shd101wyy\", \"product\": \"vscode-markdown-preview-enhanced\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 0.8.29\"}]}], \"references\": [{\"url\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch\", \"name\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/security/advisories/GHSA-427h-jhpr-8jch\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/shd101wyy/crossnote/pull/443\", \"name\": \"https://github.com/shd101wyy/crossnote/pull/443\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2320\", \"name\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/pull/2320\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/shd101wyy/crossnote/commit/e4890d64502e53b717cce0cb73f1a78b244dc640\", \"name\": \"https://github.com/shd101wyy/crossnote/commit/e4890d64502e53b717cce0cb73f1a78b244dc640\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/0d4010988c6ae56a38c6dec4a7509cbd5a7dcb4c\", \"name\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/commit/0d4010988c6ae56a38c6dec4a7509cbd5a7dcb4c\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/shd101wyy/crossnote/releases/tag/0.9.30\", \"name\": \"https://github.com/shd101wyy/crossnote/releases/tag/0.9.30\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.29\", \"name\": \"https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.29\", \"tags\": [\"x_refsource_MISC\"]}], \"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.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-94\", \"description\": \"CWE-94: Improper Control of Generation of Code (\u0027Code Injection\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-10-14T19:08:43.663Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-54566\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-14T19:45:22.736Z\", \"dateReserved\": \"2026-06-15T19:15:27.342Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-10-14T19:08:43.663Z\", \"assignerShortName\": \"GitHub_M\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…