# CVE-2025-27513: OpenTelemetry .NET has a Denial of Service (DoS) Vulnerability in API Package

> Attackers can cause denial of service via high CPU usage by sending crafted tracestate headers to applications using the OpenTelemetry .NET API.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/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:** 5 Mar 2025
- **Updated:** 5 Mar 2025
- **Also known as:** GHSA-8785-wc3w-h8q6

## What is CVE-2025-27513?

CVE-2025-27513 is a high-severity denial of service vulnerability in open-telemetry opentelemetry-dotnet, published on 5 Mar 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OpenTelemetry dotnet is a dotnet telemetry framework. A vulnerability in OpenTelemetry.Api package 1.10.0 to 1.11.1 could cause a Denial of Service (DoS) when a tracestate and traceparent header is received. Even if an application does not explicitly use trace context propagation, receiving these headers can still trigger high CPU usage. This issue impacts any application accessible over the web or backend services that process HTTP requests containing a tracestate header. Application may experience excessive resource consumption, leading to increased latency, degraded performance, or downtime. This vulnerability is fixed in 1.11.2.

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

## Which versions are affected by CVE-2025-27513?

4 open source packages ship an affected version, including OpenTelemetry.Api.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `OpenTelemetry.Api` | NuGet | All versions | None |
| `OpenTelemetry.Api` | NuGet | All versions | None |
| `OpenTelemetry.Api` | NuGet | From 1.11.0 | 1.11.2 |
| `OpenTelemetry.Api` | NuGet | From 1.11.0 | 1.11.2 |

## How do I fix CVE-2025-27513?

Upgrade OpenTelemetry.Api to 1.11.2 or later.

## Is CVE-2025-27513 being exploited?

There is no known exploitation of CVE-2025-27513 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-27513 and fix it if it is affected.

What it is: CVE-2025-27513 is a high-severity denial of service vulnerability in open-telemetry opentelemetry-dotnet, published on 5 Mar 2025. 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-2025-27513 in the wild and no public exploit code.

Affected packages and fixed versions:
- OpenTelemetry.Api (NuGet): affected all versions; no fix listed
- OpenTelemetry.Api (NuGet): affected all versions; no fix listed
- OpenTelemetry.Api (NuGet): affected from 1.11.0; fixed in 1.11.2
- OpenTelemetry.Api (NuGet): affected from 1.11.0; fixed in 1.11.2

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-2025-27513/ (Markdown: https://insights.sbomify.com/CVE-2025-27513/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-27513
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-27513
- OSV: https://osv.dev/vulnerability/CVE-2025-27513

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-27513/
Summaries are generated and may contain mistakes; the official description above is the record.