# CVE-2026-49257: mcp-pinot: Unauthenticated tool invocation via default oauth_enabled=False + host 0.0.0.0 bind

> Unauthenticated attackers can execute SQL queries and modify schemas in Apache Pinot clusters via the mcp-pinot server due to default insecure settings.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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:** 18 Jun 2026
- **Updated:** 22 Jun 2026
- **Also known as:** GHSA-73cv-556c-w3g6, PYSEC-2026-410

## What is CVE-2026-49257?

CVE-2026-49257 is a critical missing authorization vulnerability in startreedata mcp-pinot, published on 18 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

mcp-pinot is a Python-based Model Context Protocol (MCP) server for interacting with Apache Pinot. In versions 3.0.1 and below, mcp-pinot defaults to running an HTTP MCP server bound to 0.0.0.0:8080 with no authentication enabled. All MCP tools, including SQL query execution, schema creation, and table-config mutation, are reachable by any network-adjacent caller. The server proxies these calls using server-side Pinot credentials, producing a confused-deputy condition that yields full read/write access to the configured Pinot cluster. This issue has been fixed in version 3.1.0

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-49257?

3 open source packages ship an affected version, including mcp-pinot-server.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mcp-pinot-server` | PyPI | All versions | 3.1.0 |
| `mcp-pinot-server` | PyPI | All versions | 3.1.0 |
| `mcp-pinot-server` | PyPI | All versions | 3.1.0 |

## How do I fix CVE-2026-49257?

Upgrade mcp-pinot-server to 3.1.0 or later.

## Is CVE-2026-49257 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49257 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-49257 and fix it if it is affected.

What it is: CVE-2026-49257 is a critical missing authorization vulnerability in startreedata mcp-pinot, published on 18 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49257 exists.

Affected packages and fixed versions:
- mcp-pinot-server (PyPI): affected all versions; fixed in 3.1.0
- mcp-pinot-server (PyPI): affected all versions; fixed in 3.1.0
- mcp-pinot-server (PyPI): affected all versions; fixed in 3.1.0

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-2026-49257/ (Markdown: https://insights.sbomify.com/CVE-2026-49257/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49257
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49257
- OSV: https://osv.dev/vulnerability/CVE-2026-49257

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-49257/
Summaries are generated and may contain mistakes; the official description above is the record.