CVE-2026-53597highCWE-94

CVE-2026-53597: high-severity vulnerability in microsoft prompty

Prompty: Arbitrary code execution via JavaScript frontmatter in TypeScript loader

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.7epss 1.0%
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.
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
Affected products
microsoft · prompty
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