Prompty: Server-Side Template Injection to Remote Code Execution in the @prompty/core Nunjucks Renderer

Description

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.

Recommendation

Update the @prompty/core package to the latest compatible version. Followings are version details:

• Affected version(s): **>= 2.0.0-alpha.1, <= 2.0.0-beta.4

  <= 0.1.4**

• Patched version(s): **2.0.0-beta.5

  0.1.5**

References

• GHSA-w28w-gp39-m4p6
• CWE-1336
• CWE-94
• OWASP 2021-A3

Related Issues

• Strapi plugins vulnerable to Server-Side Template Injection and Remote Code Execution in the Users-Permissions Plugin - CVE-2023-22621
• @saltcorn/server Remote Code Execution (RCE) / SQL injection via prototype pollution by manipulating `lang` and `defst - Vulnerability
• Flowise: CSV Agent Prompt Injection Remote Code Execution Vulnerability - CVE-2026-41264
• Flowise: CSV Agent Prompt Injection Remote Code Execution Vulnerability - flowise-components - CVE-2026-70477

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Tags:

npm

@prompty/core