# CVE-2026-41310: OpenTelemetry .NET Zipkin exporter has unbounded remote endpoint cache leading to memory growth

> An attacker can cause memory exhaustion in applications using the OpenTelemetry .NET Zipkin exporter by sending high-cardinality span attributes, leading to service degradation.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 May 2026
- **Updated:** 7 May 2026
- **Also known as:** GHSA-88hf-wf7h-7w4m

## What is CVE-2026-41310?

CVE-2026-41310 is a medium-severity denial of service vulnerability in open-telemetry opentelemetry-dotnet, published on 6 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OpenTelemetry.Exporter.Zipkin is the .NET Zipkin exporter for OpenTelemetry. In versions 1.15.2 and earlier, the Zipkin exporter remote endpoint cache accepts unbounded key growth derived from span attributes. In high-cardinality scenarios, a process using Zipkin export for client or producer spans could experience avoidable memory growth under sustained unique remote endpoint values, increasing process memory usage over time and degrading availability. This issue is fixed in version 1.15.3, which introduces a bounded, thread-safe LRU cache for remote endpoints with a fixed maximum size.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-41310?

2 open source packages ship an affected version, including OpenTelemetry.Exporter.Zipkin. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `OpenTelemetry.Exporter.Zipkin` | NuGet | All versions | 1.15.3 |
| `OpenTelemetry.Exporter.Zipkin` | NuGet | All versions | 1.15.3 |

Products: Opentelemetry Opentelemetry.exporter.zipkin.

## How do I fix CVE-2026-41310?

Upgrade OpenTelemetry.Exporter.Zipkin to 1.15.3 or later.

## Is CVE-2026-41310 being exploited?

There is no known exploitation of CVE-2026-41310 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-41310 and fix it if it is affected.

What it is: CVE-2026-41310 is a medium-severity denial of service vulnerability in open-telemetry opentelemetry-dotnet, published on 6 May 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-2026-41310 in the wild and no public exploit code.

Affected packages and fixed versions:
- OpenTelemetry.Exporter.Zipkin (NuGet): affected all versions; fixed in 1.15.3
- OpenTelemetry.Exporter.Zipkin (NuGet): affected all versions; fixed in 1.15.3

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-2026-41310/ (Markdown: https://insights.sbomify.com/CVE-2026-41310/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41310
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41310
- OSV: https://osv.dev/vulnerability/CVE-2026-41310

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41310/
Summaries are generated and may contain mistakes; the official description above is the record.