CVE-2026-41483: open-telemetry opentelemetry-dotnet-contrib

Vulnerability summary

CVE-2026-41483 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% of scored vulnerabilities.

Timeline

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

Description

OpenTelemetry.Resources.Azure is the .NET resource detector for Azure environments. In versions 1.15.0-beta.1 and earlier, the AzureVmMetaDataRequestor class makes HTTP requests to the Azure VM instance metadata service and reads the response body into memory without any size limit. 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, disable the Azure VM resource detector or use network-level controls such as firewall rules, mTLS, or a service mesh to prevent man-in-the-middle attacks on the Azure VM instance metadata endpoint. This issue is fixed in version 1.15.1-beta.1, which streams responses rather than buffering them entirely in memory and ignores responses larger than 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.