Answer in brief
CVE-2026-73299 records a Critical severity (CVSS 10.0) vulnerability in Prompty: Server-Side Template Injection to Remote Code Execution in the @prompty/core Nunjucks Renderer. The current sources do not mark it as known exploited. The current feed maps microsoft/prompty (generic), @prompty/core (npm), @prompty/core (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 10.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps microsoft/prompty (generic), @prompty/core (npm), @prompty/core (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| microsoft/promptygeneric | < 0.1.5 || >= 2.0.0-alpha.1, < 2.0.0-beta.5 | Not reported |
| @prompty/corenpm | >=0 <0.1.5 | 0.1.5 |
| @prompty/corenpm | >=2.0.0-alpha.1 <2.0.0-beta.5 | 2.0.0-beta.5 |
Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 12, 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.
Quoted source text, attributed separately from HOL analysis.