CVE-2026-41484: open-telemetry opentelemetry-dotnet-contrib

Vulnerability summary

CVE-2026-41484 is a medium (CVSS 5.9) vulnerability in open-telemetry opentelemetry-dotnet-contrib. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.1% of scored vulnerabilities.

Timeline

1. 06-05-2026
   PublishedVulnerability first disclosed.
2. 07-05-2026
   Last modifiedVulnerability information updated.

Description

OpenTelemetry.Exporter.OneCollector is a .NET exporter that sends telemetry to a OneCollector back-end over HTTP. In versions 1.15.0 and earlier, when a request to the configured back-end or collector results in an unsuccessful HTTP 4xx or 5xx response, the HttpJsonPostTransport class reads the entire response body into memory with no upper bound on the number of bytes consumed in order to include the error response in operator logs. An attacker who controls the configured endpoint, or who can intercept traffic to it via a man-in-the-middle attack, 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. As a workaround, use network-level controls such as firewall rules, mTLS, or a service mesh to prevent man-in-the-middle attacks on the configured back-end or collector endpoint. This issue is fixed in version 1.15.1, which limits the number of bytes read from the response body in an error condition to 4 MiB.

• 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.