HomeCVE Intelligence › CVE-2026-53597
CVSS 7.5 HIGH Security Vulnerability

CVE-2026-53597: Prompty: Arbitrary code execution via JavaScript frontmatter in TypeScript loader

Summary The TypeScript Prompty loader used gray-matter without overriding executable frontmatter engines. gray-matter supports JavaScript frontmatter blocks such as ---js and evaluates them while parsing. An attacker-co…

7.5CVSS Score
HIGHSeverity
NOCISA KEV
0.9%EPSS Score
Security VulnerabilityImpact Type

📋 Vulnerability Details

CVE IDCVE-2026-53597
VendorUnknown Vendor
Affected ProductUnknown Product
Vulnerability TypeSecurity Vulnerability
CVSS Score7.5 (HIGH)
EPSS Score0.9% probability of exploitation in the next 30 days
Actively Exploited❌ No known exploitation
Patch StatusPending Vendor Disclosure
Reported ByCYBERDUDEBIVASH SENTINEL APEX Intelligence (via sentinel_apex)

🔬 Technical Analysis

#

Summary

The TypeScript Prompty loader used gray-matter without overriding executable frontmatter engines. gray-matter supports JavaScript frontmatter blocks such as ---js and evaluates them while parsing. An attacker-controlled .prompty file could therefore execute arbitrary JavaScript during prompt loading.

#

Affected package

• npm @prompty/core v2 prerelease line: >= 2.0.0-alpha.1 < 2.0.0-beta.3
• Fixed in @prompty/core@2.0.0-beta.3

The legacy v1 JavaScript runtime had a historical hardening change for this issue. During the v2 TypeScript runtime rebuild, the loader again called gray-matter directly and the vulnerable behavior was present in the v2 prerelease packages until 2.0.0-beta.3.

#

Impact

Applications that load untrusted .prompty files, user-provided p

⚡ DETECTION RULES AVAILABLE

Get CVE-2026-53597 Detection Pack

Sigma rules, YARA signatures, IOC table, and SIEM queries for Splunk, Elastic, Sentinel, and Chronicle — deployable in 5 minutes.

✓ Sigma Rules ✓ YARA Pack ✓ IOC Table ✓ SIEM Queries
🛡️ Get Detection Pack → 🔌 Access via API →

🔗 Related Intelligence