# CVE-2026-59971: MySQL MCP Server: Missing Origin/Host Validation in SSE Transport Enables Unauthenticated SQL Execution (DNS Rebinding / Direct Exposure)

> Unauthenticated attackers can execute SQL queries via SSE transport due to missing origin validation and authentication, leading to database disclosure or modification.

- **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:** 15 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-rqfv-2mw9-78g2, PYSEC-2026-4109

## What is CVE-2026-59971?

CVE-2026-59971 is a critical missing authorization vulnerability in designcomputer mysql_mcp_server, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

MySQL MCP Server is a Model Context Protocol server that enables secure interaction with MySQL databases. Prior to 0.4.2, setting MCP_TRANSPORT=sse causes src/mysql_mcp_server/server.py to construct SseServerTransport without security_settings or enable_dns_rebinding_protection, while the Starlette routes /, /sse, and /messages/ have no authentication and the service binds to 0.0.0.0 by default. A network attacker can directly reach execute_sql, or can use DNS rebinding to make a victim's browser relay same-origin requests to a locally bound service, and supply a query that reaches cursor.execute(query). This allows unauthenticated disclosure and modification of the configured database; when the MySQL account has FILE privileges, the same access can read or write server files and may enable code execution. The default stdio transport is not affected. This issue is fixed in 0.4.2.

Weakness: CWE-346 (Origin Validation Error), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-59971?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mysql-mcp-server` | PyPI | All versions | 0.4.2 |
| `mysql-mcp-server` | PyPI | All versions | 0.4.2 |
| `mysql-mcp-server` | PyPI | All versions | 0.4.2 |

## How do I fix CVE-2026-59971?

Upgrade mysql-mcp-server to 0.4.2 or later.

## Is CVE-2026-59971 being exploited?

There is no known exploitation of CVE-2026-59971 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-59971 and fix it if it is affected.

What it is: CVE-2026-59971 is a critical missing authorization vulnerability in designcomputer mysql_mcp_server, published on 15 Sep 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-2026-59971 in the wild and no public exploit code.

Affected packages and fixed versions:
- mysql-mcp-server (PyPI): affected all versions; fixed in 0.4.2
- mysql-mcp-server (PyPI): affected all versions; fixed in 0.4.2
- mysql-mcp-server (PyPI): affected all versions; fixed in 0.4.2

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-2026-59971/ (Markdown: https://insights.sbomify.com/CVE-2026-59971/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59971
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59971
- OSV: https://osv.dev/vulnerability/CVE-2026-59971

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-59971/
Summaries are generated and may contain mistakes; the official description above is the record.