CVE-2026-53597

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.9%, top 43% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
8.7
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.7Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
8.7
EG Score
8.7(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity87% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
56.9%
KEV
Not listed

Published

July 16, 2026

Last Modified

July 18, 2026

Advisory Details (2)

Auto-updated Jul 16, 2026
Patch available. Sources: github_commit, github.
github Patch Available

Arbitrary code execution via JavaScript frontmatter in TypeScript loader · Advisory · microsoft/prompty · GitHub

https://github.com/microsoft/prompty/security/advisories/GHSA-c4gh-rv8h-q9vw
github_commit

commit c27402da2487 (microsoft/prompty)

Fix landed in microsoft/prompty commit c27402da2487 — awaiting tagged release

https://github.com/microsoft/prompty/commit/c27402da2487075be577f06aa79df627fb9d6853

Vendor Advisories for CVE-2026-53597(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
@prompty/core—2.0.0-beta.3—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 12× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-23 14:18 UTCEPSS rescore
  2. 2026-07-23 03:19 UTCEG score recompute
  3. 2026-07-22 14:08 UTCEPSS rescore
  4. 2026-07-21 15:25 UTCEPSS rescore
  5. 2026-07-20 17:08 UTCEPSS rescore
  6. 2026-07-19 14:31 UTCEPSS rescore
  7. 2026-07-19 14:31 UTCEPSS rescore
  8. 2026-07-19 02:35 UTCEG score recompute
  9. 2026-07-19 02:29 UTCEPSS rescore
  10. 2026-07-18 10:04 UTCEPSS rescore
  11. 2026-07-16 15:24 UTCEG score recompute
  12. 2026-07-16 15:23 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-53597?
CVE-2026-53597 is a high vulnerability published on July 16, 2026. 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…
When was CVE-2026-53597 disclosed?
CVE-2026-53597 was first published in the National Vulnerability Database on July 16, 2026, with the most recent update on July 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53597 actively exploited?
CVE-2026-53597 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 56.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-53597?
CVE-2026-53597 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-53597?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53597, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-53597

Explore →

Is Your Infrastructure Affected by CVE-2026-53597?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs