CVE-2026-41173: open-telemetry opentelemetry-dotnet-contrib

Vulnerability summary

CVE-2026-41173 is a medium (CVSS 5.9) vulnerability in open-telemetry opentelemetry-dotnet-contrib. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.3% of scored vulnerabilities.

Timeline

1. 23-04-2026
   PublishedVulnerability first disclosed.
2. 23-04-2026
   Last modifiedVulnerability information updated.

Description

The AWS X-Ray Remote Sampler package provides a sampler which can get sampling configurations from AWS X-Ray. Prior to 0.1.0-alpha.8, OpenTelemetry.Sampler.AWS reads unbounded HTTP response bodies from a configured AWS X-Ray remote sampling endpoint into memory. AWSXRaySamplerClient.DoRequestAsync called HttpClient.SendAsync followed by ReadAsStringAsync(), which materializes the entire HTTP response body into a single in-memory string with no size limit. The sampling endpoint is configurable via AWSXRayRemoteSamplerBuilder.SetEndpoint (default: http://localhost:2000). An attacker who controls the configured endpoint, or who can intercept traffic to it (MitM), can return an arbitrarily large response body. This causes unbounded heap allocation in the consuming process, leading to high transient memory pressure, garbage-collection stalls, or an OutOfMemoryException that terminates the process. This vulnerability is fixed in 0.1.0-alpha.8.

• CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.