CVE-2026-44902 in opentelemetry-js
Summary
by MITRE • 05/27/2026
opentelemetry-js is the OpenTelemetry JavaScript Client. Prior to 0.217.0, a single malformed HTTP request crashes any Node.js process running the OpenTelemetry JS Prometheus exporter. The metrics endpoint (default 0.0.0.0:9464) has no error handling around URL parsing, so a request with an invalid URI causes an uncaught TypeError that terminates the process. This vulnerability is fixed in 0.217.0.
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Analysis
by VulDB Data Team • 07/08/2026
The OpenTelemetry JavaScript client represents a critical infrastructure component for observability and monitoring in modern web applications, particularly within Node.js environments where distributed tracing and metrics collection are essential for system health assessment. The vulnerability described affects versions prior to 0217.0 of the OpenTelemetry JS Prometheus exporter, which serves as a bridge between application metrics and monitoring systems through its default endpoint at 0.0.0.0:9464. This exporter exposes HTTP endpoints that collect and expose metrics data in a format compatible with Prometheus scraping mechanisms, making it an attractive target for both legitimate monitoring operations and potential exploitation scenarios.
The technical flaw manifests as a lack of proper input validation and error handling within the URL parsing logic of the Prometheus exporter's HTTP request processing pipeline. When a malformed HTTP request reaches the metrics endpoint, the system fails to gracefully handle the invalid URI structure that causes a TypeError exception to propagate through the Node.js process execution flow without being caught by any error handlers. This particular vulnerability stems from the absence of defensive programming practices in the parsing functions that process incoming HTTP requests before they are processed for metric collection and export.
The operational impact of this vulnerability extends beyond simple service disruption, as it represents a denial-of-service condition that can terminate entire Node.js processes without proper recovery mechanisms. When an uncaught TypeError occurs during URL parsing, the Node.js runtime immediately terminates the process execution, requiring manual intervention or automated restart procedures to restore monitoring capabilities. This creates a dangerous scenario where the very system designed to monitor application health becomes a potential point of failure that could mask actual application issues while simultaneously preventing the collection of critical metrics data.
Organizations relying on OpenTelemetry JS for monitoring their Node.js applications face significant operational risks when running vulnerable versions, as any malformed request to the exposed metrics endpoint can result in complete service interruption. The vulnerability's exploitation potential increases when considering that such malformed requests could be generated by automated scanning tools or malicious actors attempting to disrupt services, particularly in environments where the default Prometheus endpoint is accessible from untrusted networks. This scenario represents a classic example of a path traversal or input validation vulnerability that demonstrates the importance of robust error handling and defensive programming practices.
The fix implemented in version 0.217.0 addresses this issue through proper error handling mechanisms that catch malformed URI parsing errors before they can propagate as uncaught exceptions. This remediation aligns with industry best practices for secure coding and follows established patterns for input validation and error management as outlined in CWE-248, which specifically addresses the issue of uncaught exceptions in software systems. The solution demonstrates adherence to security principles that prevent single points of failure in monitoring infrastructure, ensuring that monitoring systems can maintain operational integrity even when subjected to malformed inputs.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1499.004 for network denial-of-service attacks and represents a critical weakness in the system's resilience against malformed input conditions. The fix reinforces proper exception handling patterns that are essential for maintaining service availability and demonstrates the importance of implementing comprehensive error handling strategies in monitoring and observability systems. Organizations should prioritize updating to version 0.217.0 or later to protect their monitoring infrastructure from potential service disruption attacks while maintaining the integrity of their application health monitoring capabilities.
The vulnerability highlights fundamental security considerations that organizations must address when implementing monitoring solutions, particularly those exposed through network endpoints. Proper input validation and error handling represent basic but critical security controls that prevent simple malformed inputs from causing catastrophic system failures. This case study serves as a reminder that even monitoring infrastructure components require robust security design principles to maintain operational reliability and prevent exploitation of seemingly minor implementation flaws that could have significant impact on system availability.