CVE-2026-53597
Full vulnerability record from the local CVENow database.
Description
Prompty is a markdown file format (.prompty) for LLM prompts. From 2.0.0-alpha.1 until 2.0.0-beta.3, the @prompty/core TypeScript loader in runtime/typescript/packages/core/src/core/loader.ts used gray-matter without overriding executable js and javascript frontmatter engines, allowing an attacker-controlled .prompty file with ---js frontmatter to execute arbitrary JavaScript during prompt loading. This issue is fixed in version 2.0.0-beta.3.
Severity
HIGH
CVSS score
8.7
(v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-07-16 16:19:12.860000
Last modified
2026-10-24 20:10:00.137000
View original CVE JSON
{
"id": "CVE-2026-53597",
"sourceIdentifier": "[email protected]",
"published": "2026-07-16T16:19:12.860",
"lastModified": "2026-10-24T20:10:00.137",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Prompty is a markdown file format (.prompty) for LLM prompts. From 2.0.0-alpha.1 until 2.0.0-beta.3, the @prompty/core TypeScript loader in runtime/typescript/packages/core/src/core/loader.ts used gray-matter without overriding executable js and javascript frontmatter engines, allowing an attacker-controlled .prompty file with ---js frontmatter to execute arbitrary JavaScript during prompt loading. This issue is fixed in version 2.0.0-beta.3."
},
{
"lang": "es",
"value": "Prompty es un formato de archivo markdown (.prompty) para prompts de LLM. Desde la 2.0.0-alpha.1 hasta la 2.0.0-beta.3, el cargador TypeScript @prompty/core en runtime/typescript/packages/core/src/core/loader.ts utilizaba gray-matter sin anular los motores de frontmatter ejecutables js y javascript, lo que permitía que un archivo .prompty controlado por un atacante con frontmatter ---js ejecutara JavaScript arbitrario durante la carga del prompt. Este problema se solucionó en la versión 2.0.0-beta.3."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "microsoft",
"product": "prompty",
"versions": [
{
"version": ">= 2.0.0-alpha.1, < 2.0.0-beta.3",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"userInteraction": "PASSIVE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"vulnAvailabilityImpact": "HIGH",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"subAvailabilityImpact": "NONE",
"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-07-18T02:50:54.007782Z",
"id": "CVE-2026-53597",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-94"
}
]
}
],
"references": [
{
"url": "https://github.com/microsoft/prompty/commit/c27402da2487075be577f06aa79df627fb9d6853",
"source": "[email protected]"
},
{
"url": "https://github.com/microsoft/prompty/security/advisories/GHSA-c4gh-rv8h-q9vw",
"source": "[email protected]"
}
]
}