CVE-2026-53597: 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/cor

unknownCVE-2026-53597

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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: unknown
Published: 2026-07-16
Last updated: 2026-07-18
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-53597

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-535970.93% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 57% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-53597	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

highGHSA-c4gh-rv8h-q9vw: Prompty: Arbitrary code execution via JavaScript frontmatter in TypeScript loaderghsa

Recent advisories for Prompty is a

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

criticalGHSA-w28w-gp39-m4p6: Prompty: Server-Side Template Injection to Remote Code Execution in the @prompty/core Nun…ghsa · 2026-07-24
highGHSA-c4gh-rv8h-q9vw: Prompty: Arbitrary code execution via JavaScript frontmatter in TypeScript loaderghsa · 2026-07-17
highGHSA-wxhm-2mq7-7697: Prompty: Arbitrary file read via file reference expansionghsa · 2026-07-17
highCVE-2026-53598: Prompty is a markdown file format (.prompty) for LLM prompts. Prior to 2.0.0-beta.2, Prompty l…nvd · 2026-07-16