What’s Vulnerable › Vulnerabilities

CVE-2026-40182: OpenTelemetry dotnet: OTLP exporter reads unbounded HTTP response bodies

• Severity: medium (CVSS 5.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-23 · updated 2026-10-26
• Weakness: CWE-789

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.

Affected products

• open-telemetry opentelemetry-go: from 1.13.1 before 1.15.2 — fixed in 1.15.2

How to fix

Upgrade to a fixed version: open-telemetry opentelemetry-go 1.15.2. Check the vendor advisory for mitigations.

References

• https://github.com/open-telemetry/opentelemetry-dotnet/pull/6564
• https://github.com/open-telemetry/opentelemetry-dotnet/pull/7017
• https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-q834-8qmm-v933
• https://github.com/open-telemetry/opentelemetry-proto/pull/781

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