CVE-2026-73299
Published:August 12, 2026
Updated:August 24, 2026
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.
Affected Packages
https://github.com/microsoft/prompty.git (GITHUB):
Affected version(s) >=typescript/2.0.0-alpha.3 <typescript/2.0.0-beta.5Fix Suggestion:
Update to version typescript/2.0.0-beta.5@prompty/core (NPM):
Affected version(s) >=0.0.1 <0.1.5Fix Suggestion:
Update to version 0.1.5@prompty/core (NPM):
Affected version(s) >=2.0.0-alpha.1 <2.0.0-beta.5Fix Suggestion:
Update to version 2.0.0-beta.5Related Resources (10)
Do you need more information?
Contact UsCVSS v4
Base Score:
10
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
HIGH
CVSS v3
Base Score:
10
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
EPSS
Base Score:
1.21