Description
Prompty is a markdown file format (.prompty) for LLM prompts. Prior to 0.1.5 and 2.0.0-beta.5, the TypeScript Nunjucks renderer evaluated untrusted .prompty template bodies with unrestricted JavaScript member access. An attacker-controlled template could traverse constructor and prototype properties to execute JavaScript in the host Node.js process. This issue is fixed in versions 0.1.5 and 2.0.0-beta.5.
Published: 2026-08-12
Score: 10 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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History

Wed, 12 Aug 2026 20:15:00 +0000

Type Values Removed Values Added
First Time appeared Microsoft
Microsoft prompty
Vendors & Products Microsoft
Microsoft prompty

Wed, 12 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Wed, 12 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
Description Prompty is a markdown file format (.prompty) for LLM prompts. Prior to 0.1.5 and 2.0.0-beta.5, the TypeScript Nunjucks renderer evaluated untrusted .prompty template bodies with unrestricted JavaScript member access. An attacker-controlled template could traverse constructor and prototype properties to execute JavaScript in the host Node.js process. This issue is fixed in versions 0.1.5 and 2.0.0-beta.5.
Title Prompty: Server-Side Template Injection to Remote Code Execution in the @prompty/core Nunjucks Renderer
Weaknesses CWE-1336
CWE-94
References
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}


Subscriptions

Microsoft Prompty
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-12T18:54:20.646Z

Reserved: 2026-08-11T19:42:11.450Z

Link: CVE-2026-73299

cve-icon Vulnrichment

Updated: 2026-08-12T18:54:13.109Z

cve-icon NVD

Status : Received

Published: 2026-08-12T18:18:15.197

Modified: 2026-08-12T20:17:53.920

Link: CVE-2026-73299

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-12T20:00:03Z

Weaknesses
  • CWE-1336

    Improper Neutralization of Special Elements Used in a Template Engine

  • CWE-94

    Improper Control of Generation of Code ('Code Injection')