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 r…
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 by source
- 2026-08-12
- First seen by Reality Radar
- 2026-10-23
- Last verified
- 2026-10-23
What the official notice says
Risk: critical severity (CVSS 10)
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Sources
- NIST National Vulnerability Database Tier A · official published 2026-08-12
Evidence ledger
Every piece of evidence we store is appended to a public hash chain, so later edits are detectable. Anyone can re-verify it.
| Entry | Kind | Observed | Evidence hash | Entry hash |
|---|---|---|---|---|
| #1298 | new | 2026-10-23 | 5fac53e581be…1ec672 | a88b36d6dd3f…ef2763 |
Chain head: #1479 ad3417dbc128…777bd4