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: 1.0%, top 41% 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
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.7Exploit: None knownExposed: 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 PROB
1%
EPSS %ILE
60%
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 12× in last 7d / 53× 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. 2026-09-01 13:54 UTCEPSS rescore
  2. 2026-09-01 04:40 UTCEPSS rescore
  3. 2026-08-31 03:51 UTCEG score recompute
  4. 2026-08-30 19:17 UTCEPSS rescore
  5. 2026-08-30 03:35 UTCEG score recompute
  6. 2026-08-30 01:22 UTCEPSS rescore
  7. 2026-08-28 21:41 UTCEPSS rescore
  8. 2026-08-28 01:50 UTCEG score recompute
  9. 2026-08-27 14:25 UTCEPSS rescore
  10. 2026-08-27 00:47 UTCEG score recompute
  11. 2026-08-26 14:46 UTCEPSS rescore
  12. 2026-08-26 00:58 UTCEG score recompute
  13. 2026-08-25 13:49 UTCEPSS rescore
  14. 2026-08-25 00:12 UTCEG score recompute
  15. 2026-08-24 12:16 UTCEG score recompute
  16. 2026-08-23 12:12 UTCEG score recompute
  17. 2026-08-23 00:19 UTCEPSS rescore
  18. 2026-08-22 00:01 UTCEG score recompute
  19. 2026-08-21 23:49 UTCEPSS rescore
  20. 2026-08-21 00:10 UTCEG score recompute
  21. 2026-08-20 22:55 UTCEPSS rescore
  22. 2026-08-19 23:55 UTCEG score recompute
  23. 2026-08-19 17:04 UTCEPSS rescore
  24. 2026-08-18 19:56 UTCEG score recompute
  25. 2026-08-18 13:48 UTCEPSS rescore
Show 56 more
  1. 2026-08-17 00:55 UTCEG score recompute
  2. 2026-08-16 14:56 UTCEPSS rescore
  3. 2026-08-16 13:00 UTCEG score recompute
  4. 2026-08-16 02:14 UTCEPSS rescore
  5. 2026-08-15 13:11 UTCEG score recompute
  6. 2026-08-15 01:30 UTCEPSS rescore
  7. 2026-08-14 01:27 UTCEG score recompute
  8. 2026-08-13 22:00 UTCEPSS rescore
  9. 2026-08-13 01:38 UTCEG score recompute
  10. 2026-08-12 13:51 UTCEPSS rescore
  11. 2026-08-11 13:55 UTCEG score recompute
  12. 2026-08-11 02:01 UTCEG score recompute
  13. 2026-08-11 00:00 UTCEPSS rescore
  14. 2026-08-09 14:17 UTCEG score recompute
  15. 2026-08-09 13:46 UTCEPSS rescore
  16. 2026-08-09 02:23 UTCEG score recompute
  17. 2026-08-08 16:37 UTCEPSS rescore
  18. 2026-08-08 02:34 UTCEG score recompute
  19. 2026-08-06 14:50 UTCEG score recompute
  20. 2026-08-06 13:47 UTCEPSS rescore
  21. 2026-08-06 02:55 UTCEG score recompute
  22. 2026-08-05 19:17 UTCEPSS rescore
  23. 2026-08-05 00:55 UTCEG score recompute
  24. 2026-08-04 15:10 UTCEPSS rescore
  25. 2026-08-04 13:01 UTCEG score recompute
  26. 2026-08-04 10:39 UTCEPSS rescore
  27. 2026-08-03 11:58 UTCEG score recompute
  28. 2026-08-03 10:36 UTCEPSS rescore
  29. 2026-08-02 11:18 UTCEG score recompute
  30. 2026-08-02 02:27 UTCEPSS rescore
  31. 2026-08-01 11:28 UTCEG score recompute
  32. 2026-08-01 04:16 UTCEPSS rescore
  33. 2026-07-30 23:39 UTCEG score recompute
  34. 2026-07-30 16:28 UTCEPSS rescore
  35. 2026-07-30 11:44 UTCEG score recompute
  36. 2026-07-30 01:30 UTCEPSS rescore
  37. 2026-07-28 23:50 UTCEG score recompute
  38. 2026-07-28 15:37 UTCEPSS rescore
  39. 2026-07-27 23:44 UTCEG score recompute
  40. 2026-07-26 23:23 UTCEG score recompute
  41. 2026-07-26 14:54 UTCEPSS rescore
  42. 2026-07-26 11:25 UTCEG score recompute
  43. 2026-07-25 14:18 UTCEPSS rescore
  44. 2026-07-24 14:18 UTCEPSS rescore
  45. 2026-07-23 14:18 UTCEPSS rescore
  46. 2026-07-23 03:19 UTCEG score recompute
  47. 2026-07-22 14:08 UTCEPSS rescore
  48. 2026-07-21 15:25 UTCEPSS rescore
  49. 2026-07-20 17:08 UTCEPSS rescore
  50. 2026-07-19 14:31 UTCEPSS rescore
  51. 2026-07-19 14:31 UTCEPSS rescore
  52. 2026-07-19 02:35 UTCEG score recompute
  53. 2026-07-19 02:29 UTCEPSS rescore
  54. 2026-07-18 10:04 UTCEPSS rescore
  55. 2026-07-16 15:24 UTCEG score recompute
  56. 2026-07-16 15:23 UTCMITRE cvelistV5first tracked

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 1% probability of exploitation in the next 30 days, which ranks it in the top 40.5% of all scored CVEs.
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

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