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CVE-2026-53597 is a remote code execution vulnerability in Microsoft Prompty’s TypeScript implementation, specifically the @prompty/core loader used to parse .prompty files. In affected versions from 2.0.0-alpha.1 through 2.0.0-beta.2, the loader invoked the gray-matter library on raw .prompty content without disabling its executable js and javascript frontmatter engines. As a result, an attacker-controlled .prompty file containing JavaScript frontmatter could trigger arbitrary JavaScript execution during prompt loading. The vulnerable code path is in the TypeScript loader component at runtime/typescript/packages/core/src/core/loader.ts. The issue was fixed in version 2.0.0-beta.3 by explicitly overriding the js and javascript frontmatter engines so executable frontmatter is rejected rather than parsed and executed.
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A remote code execution vulnerability in Microsoft's @prompty/core TypeScript loader caused by unsafe parsing of .prompty frontmatter via gray-matter, allowing attacker-controlled JavaScript in frontmatter to execute during file ingestion.
A separately listed remote code execution vulnerability in Microsoft prompty mentioned only in related content.
An arbitrary JavaScript execution vulnerability in Microsoft Prompty's @prompty/core TypeScript loader caused by unsafe handling of executable js/javascript frontmatter in gray-matter when loading attacker-controlled .prompty files.
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Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.