CVE-2026-73299
Prompty code injection
- Published12 Aug 2026
Description
Prompty is a markdown file format (.prompty) for LLM prompts. Prior to 0.1.5 and 2.0.0-beta.5, the TypeScript Nunjucks renderer evaluated untrusted .prompty template bodies with unrestricted JavaScript member access. An attacker-controlled template could traverse constructor and prototype properties to execute JavaScript in the host Node.js process. This issue is fixed in versions 0.1.5 and 2.0.0-beta.5.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HRemediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
References
- https://github.com/microsoft/prompty/commit/e4a0ebf49e3a78d5d7796c8480bf9a4f0c54d19e
- https://github.com/microsoft/prompty/commit/f5c57c94a0990cca79d095c3daab661b4b1fb89f
- https://github.com/microsoft/prompty/pull/404
- https://github.com/microsoft/prompty/pull/405
- https://github.com/microsoft/prompty/security/advisories/GHSA-w28w-gp39-m4p6
- https://github.com/microsoft/prompty/tree/typescript/2.0.0-beta.5
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-73299 being actively exploited?
CVE-2026-73299 is not in the CISA KEV catalog. Its EPSS exploit probability is 1.78%.
How severe is CVE-2026-73299?
CVE-2026-73299 has a CVSS 3.1 base score of 10.0, rated critical. EPSS estimates a 1.78% probability of exploitation.
How do I fix CVE-2026-73299?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-73299 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.