CVE-2026-53597
Prompty: Arbitrary code execution via JavaScript frontmatter in TypeScript loader
Description
Prompty is a markdown file format (.prompty) for LLM prompts. From 2.0.0-alpha.1 until 2.0.0-beta.3, the @prompty/core TypeScript loader in runtime/typescript/packages/core/src/core/loader.ts used gray-matter without overriding executable js and javascript frontmatter engines, allowing an attacker-controlled .prompty file with ---js frontmatter to execute arbitrary JavaScript during prompt loading. This issue is fixed in version 2.0.0-beta.3.
INFO
Published Date :
July 16, 2026, 4:19 p.m.
Last Modified :
July 16, 2026, 4:19 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-53597
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update @prompty/core to version 2.0.0-beta.3 or later.
- Ensure prompt loading mechanism does not execute frontmatter code.
- Review dependencies for similar vulnerabilities.
- Sanitize or validate frontmatter content.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-53597.
| URL | Resource |
|---|---|
| https://github.com/microsoft/prompty/commit/c27402da2487075be577f06aa79df627fb9d6853 | |
| https://github.com/microsoft/prompty/security/advisories/GHSA-c4gh-rv8h-q9vw |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53597 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-53597
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-53597 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53597 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Jul. 16, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'microsoft', 'product': 'prompty', 'versions': [{'status': 'affected', 'version': '>= 2.0.0-alpha.1, < 2.0.0-beta.3'}]}] Added Description Prompty is a markdown file format (.prompty) for LLM prompts. From 2.0.0-alpha.1 until 2.0.0-beta.3, the @prompty/core TypeScript loader in runtime/typescript/packages/core/src/core/loader.ts used gray-matter without overriding executable js and javascript frontmatter engines, allowing an attacker-controlled .prompty file with ---js frontmatter to execute arbitrary JavaScript during prompt loading. This issue is fixed in version 2.0.0-beta.3. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-94 Added Reference https://github.com/microsoft/prompty/commit/c27402da2487075be577f06aa79df627fb9d6853 Added Reference https://github.com/microsoft/prompty/security/advisories/GHSA-c4gh-rv8h-q9vw