CVE-2026-73299

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.

CVSS v3 10.0 CRITICAL

10.0^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/microsoft/prompty/commit/e4a0ebf49e3a78d5d7796c8480bf9a4f0c54d19e
https://github.com/microsoft/prompty/commit/f5c57c94a0990cca79d095c3daab661b4b1fb89f
https://github.com/microsoft/prompty/pull/404
https://github.com/microsoft/prompty/pull/405
https://github.com/microsoft/prompty/security/advisories/GHSA-w28w-gp39-m4p6
https://github.com/microsoft/prompty/tree/typescript/2.0.0-beta.5

Configurations

No configuration.

History

23 Oct 2026, 19:10

Type	Values Removed	Values Added
Summary		(es) Prompty es un formato de archivo markdown (.prompty) para prompts de LLM. Antes de las versiones 0.1.5 y 2.0.0-beta.5, el renderizador TypeScript Nunjucks evaluaba cuerpos de plantillas .prompty no confiables con acceso irrestricto a miembros de JavaScript. Una plantilla controlada por el atacante podría recorrer propiedades de constructor y prototipo para ejecutar JavaScript en el proceso host de Node.js. Este problema está solucionado en las versiones 0.1.5 y 2.0.0-beta.5.

Information

Published : 2026-08-12 18:18

Updated : 2026-10-24 15:10

NVD link : CVE-2026-73299

Mitre link : CVE-2026-73299

CVE.ORG link : CVE-2026-73299

JSON object : View

Products Affected

No product.

CWE

CWE-94

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

CWE-1336

Improper Neutralization of Special Elements Used in a Template Engine

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