Arbitrary Code Execution in Prompty by Microsoft
CVE-2026-53597

8.7HIGH

Key Information:

Vendor

Microsoft
Status
Prompty
Vendor
CVE Published:
16 July 2026

What is CVE-2026-53597?

A vulnerability in the Prompty product allows for arbitrary JavaScript code execution due to improper handling of frontmatter in markdown files. The issue arises when using the @prompty/core TypeScript loader, primarily affecting versions from 2.0.0-alpha.1 through 2.0.0-beta.3. Attackers can exploit this flaw by crafting a malicious .prompty file that includes JavaScript frontmatter, enabling them to execute untrusted code during the prompt loading process. This significant security concern has been addressed in version 2.0.0-beta.3.

Affected Version(s)

prompty >= 2.0.0-alpha.1, < 2.0.0-beta.3

References

https://github.com/microsoft/prompty/security/advisories/...
x_refsource_CONFIRM
https://github.com/microsoft/prompty/commit/c27402da24870...
x_refsource_MISC

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.