# CVE-2026-116477: a2aproject a2a-dotnet Parser A2AJsonRpcProcessor.cs A2AJsonRpcProcessor.ProcessRequestAsync information exposure


- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 26 Oct 2026
- **Updated:** 26 Oct 2026
- **Also known as:** GHSA-6fjg-cx22-jv29

## What is CVE-2026-116477?

CVE-2026-116477 is a medium-severity vulnerability in a2aproject a2a-dotnet, published on 26 Oct 2026. 

### Official description

A security vulnerability has been detected in a2aproject a2a-dotnet up to 1.0.0-preview2. The impacted element is the function A2AJsonRpcProcessor.ProcessRequestAsync of the file src/A2A.AspNetCore/A2AJsonRpcProcessor.cs of the component Parser. The manipulation leads to information exposure through error message. It is possible to initiate the attack remotely. Upgrading to version 1.0.0-preview3 is sufficient to resolve this issue. The identifier of the patch is ccbd12b6108a6a8f0fd5d8b4a9ece3c8a94ba1e4. Upgrading the affected component is recommended.

Weakness: CWE-209 (Generation of Error Message Containing Sensitive Information), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-116477?


## How do I fix CVE-2026-116477?

No fix has been published for CVE-2026-116477 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-116477 being exploited?

There is no known exploitation of CVE-2026-116477 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-116477 and fix it if it is affected.

What it is: CVE-2026-116477 is a medium-severity vulnerability in a2aproject a2a-dotnet, published on 26 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-116477 in the wild and no public exploit code.

Affected product: a2aproject a2a-dotnet. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-116477/ (Markdown: https://insights.sbomify.com/CVE-2026-116477/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-116477
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116477
- OSV: https://osv.dev/vulnerability/CVE-2026-116477

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-116477/
Summaries are generated and may contain mistakes; the official description above is the record.