CVE-2026-53597
Arbitrary JS execution via .prompty frontmatter in @prompty/core <2.0.0-beta.3
Is CVE-2026-53597 being exploited?
Not confirmed. CVE-2026-53597 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.97% probability of exploitation in the next 30 days.
How severe is CVE-2026-53597?
CVE-2026-53597 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-53597?
Yes. A fix has been recorded for CVE-2026-53597. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-53597 affect?
CVE-2026-53597 affects @prompty/core TypeScript loader 2.0.0-alpha.1..2.0.0-beta.3, .prompty files and LLM prompt pipelines using Prompty. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-53597?
Upgrade @prompty/core to >=2.0.0-beta.3 and validate/trust .prompty inputs
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attacker-controlled .prompty ---js frontmatter executes arbitrary JavaScript during prompt loading, enabling code execution, data exfiltration, or supply-chain compromise where loader runs.
Patch when possible
- affected>= 2.0.0-alpha.1 and < 2.0.0-beta.3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.