CVE-2026-40182: open-telemetry opentelemetry-dotnet

Vulnerability summary

CVE-2026-40182 is a medium (CVSS 5.9) vulnerability in open-telemetry opentelemetry-dotnet. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 45.4% of scored vulnerabilities.

Timeline

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

Description

OpenTelemetry dotnet is a dotnet telemetry framework. From 1.13.1 to before 1.15.2, When exporting telemetry to a back-end/collector over gRPC or HTTP using OpenTelemetry Protocol format (OTLP), if the request results in a unsuccessful request (i.e. HTTP 4xx or 5xx), the response is read into memory with no upper-bound on the number of bytes consumed. This could cause memory exhaustion in the consuming application if the configured back-end/collector endpoint is attacker-controlled (or a network attacker can MitM the connection) and an extremely large body is returned by the response. This vulnerability is fixed in 1.15.2.

• CWE-789Memory Allocation with Excessive Size ValueThe product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.