CVE-2026-44902: OpenTelemetry opentelemetry-js denial of service in Prometheus exporter

Executive brief

A vulnerability in the OpenTelemetry Prometheus exporter for Node.js allows an unauthenticated attacker to crash the entire application process. By sending a single specially crafted web request to the metrics endpoint, an attacker can trigger a fatal error that shuts down the service. This results in a complete denial of service for any application using this monitoring component.

Technical details

The vulnerability is an unhandled exception (TypeError) in the `_requestHandler` of `PrometheusExporter.ts`. When the exporter's built-in HTTP server receives a malformed absolute-form URI (e.g., 'http://'), the `new URL()` constructor throws an 'Invalid URL' error. Because this call is not wrapped in a try-catch block, the exception propagates to the top level, causing the Node.js process to terminate. This can be exploited by an unauthenticated remote attacker with network access to the metrics port (default 9464). Patches are available in @opentelemetry/exporter-prometheus v0.217.0 and @opentelemetry/auto-instrumentations-node v0.75.0.

Affected products

• OpenTelemetry @opentelemetry/exporter-prometheus < 0.217.0
• OpenTelemetry @opentelemetry/sdk-node < 0.217.0
• OpenTelemetry @opentelemetry/auto-instrumentations-node < 0.75.0

Timeline

• 2026-05-11: advisory: GitHub Advisory published
• 2026-05-27: other: NVD published date

References

• https://api.github.com/users/homanp
• https://github.com/homanp
• https://api.github.com/users/homanp/gists%7B/gist_id%7D
• https://api.github.com/users/homanp/repos
• https://avatars.githubusercontent.com/u/2464556?v=4
• https://api.github.com/users/homanp/events%7B/privacy%7D