# CVE-2026-41173: Unbounded HTTP response body read in OpenTelemetry.Sampler.AWS

> An attacker controlling the sampling endpoint can cause memory exhaustion and process termination by returning large HTTP responses.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Apr 2026
- **Updated:** 23 Apr 2026
- **Also known as:** GHSA-28xm-prxc-5866

## What is CVE-2026-41173?

CVE-2026-41173 is a medium-severity denial of service vulnerability in open-telemetry opentelemetry-dotnet-contrib, published on 23 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The AWS X-Ray Remote Sampler package provides a sampler which can get sampling configurations from AWS X-Ray. Prior to 0.1.0-alpha.8, OpenTelemetry.Sampler.AWS reads unbounded HTTP response bodies from a configured AWS X-Ray remote sampling endpoint into memory.  AWSXRaySamplerClient.DoRequestAsync called HttpClient.SendAsync followed by ReadAsStringAsync(), which materializes the entire HTTP response body into a single in-memory string with no size limit. The sampling endpoint is configurable via AWSXRayRemoteSamplerBuilder.SetEndpoint (default: http://localhost:2000). An attacker who controls the configured endpoint, or who can intercept traffic to it (MitM), 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. This vulnerability is fixed in 0.1.0-alpha.8.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-41173?

4 open source packages ship an affected version, including OpenTelemetry.Resources.AWS and OpenTelemetry.Sampler.AWS.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `OpenTelemetry.Resources.AWS` | NuGet | All versions | 1.15.1 |
| `OpenTelemetry.Resources.AWS` | NuGet | All versions | 1.15.1 |
| `OpenTelemetry.Sampler.AWS` | NuGet | All versions | 0.1.0-alpha.8 |
| `OpenTelemetry.Sampler.AWS` | NuGet | All versions | 0.1.0-alpha.8 |

## How do I fix CVE-2026-41173?

Upgrade OpenTelemetry.Resources.AWS to 1.15.1 or later.

## Is CVE-2026-41173 being exploited?

There is no known exploitation of CVE-2026-41173 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-41173 and fix it if it is affected.

What it is: CVE-2026-41173 is a medium-severity denial of service vulnerability in open-telemetry opentelemetry-dotnet-contrib, published on 23 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-41173 in the wild and no public exploit code.

Affected packages and fixed versions:
- OpenTelemetry.Resources.AWS (NuGet): affected all versions; fixed in 1.15.1
- OpenTelemetry.Resources.AWS (NuGet): affected all versions; fixed in 1.15.1
- OpenTelemetry.Sampler.AWS (NuGet): affected all versions; fixed in 0.1.0-alpha.8
- OpenTelemetry.Sampler.AWS (NuGet): affected all versions; fixed in 0.1.0-alpha.8

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-41173/ (Markdown: https://insights.sbomify.com/CVE-2026-41173/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41173
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41173
- OSV: https://osv.dev/vulnerability/CVE-2026-41173

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41173/
Summaries are generated and may contain mistakes; the official description above is the record.