CVE-2026-53597 Details
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.
A vulnerability in the Prompty markdown file loader for LLM prompts, specifically in versions 2.0.0-alpha.1 prior to 2.0.0-beta.3, allows for arbitrary JavaScript execution. The issue arises because the TypeScript loader used gray-matter for frontmatter parsing without disabling executable JavaScript in the frontmatter. This oversight enabled an attacker to craft a .prompty file with JavaScript frontmatter that would be executed during the loading process. The vulnerability has been addressed in version 2.0.0-beta.3.
Users should upgrade to Prompty version 2.0.0-beta.3 or later, which disables the execution of JavaScript frontmatter in .prompty files.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 16, 2026CISA-ADP
Assessed Jul 18, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/microsoft/prompty/commit/c27402da2487075be577f06aa79df627fb9d6853 | [email protected] | Source CodeVendor |
| https://github.com/microsoft/prompty/security/advisories/GHSA-c4gh-rv8h-q9vw | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-94 | Improper Control of Generation of Code ('Code Injection') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Microsoft Prompty | All versions |
CPE
Remediation
| |
| Microsoft Prompty Core | >= 2.0.0-alpha.1, < 2.0.0-beta.3 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 18, 2026 | CVE Modified | CISA-ADP |
| Jul 16, 2026 | New CVE Received | [email protected] |