CVE-2026-73299
Remote code execution via Prompty (.prompty) template evaluation in Node.js
Is CVE-2026-73299 being exploited?
Not confirmed. CVE-2026-73299 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 1.2% probability of exploitation in the next 30 days.
How severe is CVE-2026-73299?
CVE-2026-73299 is rated Critical with a CVSS score of 10.0. 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-2026-73299?
Yes. A fix has been recorded for CVE-2026-73299. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-73299 affect?
CVE-2026-73299 affects prompty versions < 0.1.5, prompty versions < 2.0.0-beta.5, TypeScript Nunjucks renderer in Node.js apps, Any app evaluating untrusted .prompty templates. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-73299?
Upgrade prompty to >=0.1.5 or >=2.0.0-beta.5 and stop evaluating untrusted templates.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attacker-supplied .prompty templates can traverse prototypes to execute arbitrary JavaScript in the host Node.js process (RCE, data theft, full server compromise).
Immediate action required
- affected< 0.1.5
- affected>= 2.0.0-alpha.1 and < 2.0.0-beta.5
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.