RCE in Microsoft Prompty
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…
Vulnerability class: RCE (Remote Code Execution)
CVSS v3 metric
CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Microsoft Prompty — versions < 0.1.5, >= 2.0.0-alpha.1, < 2.0.0-beta.5
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-73299?
- CVE-2026-73299 is a critical-severity vulnerability in Microsoft Prompty, classified under Code Injection. CVSS score: 10.0/10. Published 2026-08-12.
- How severe is CVE-2026-73299?
- Critical severity. CVSS v3 base score is 10.0 out of 10.