---
title: "CVE-2026-59971: MySQL MCP Server: Missing Origin/Host Validation in SSE Transport Enables Unauthenticated SQL Execution (DNS Rebinding / Direct Exposure)"
url: https://erroneo.us/security/cve/CVE-2026-59971/
description: "CVE-2026-59971 (mysql-mcp-server (PyPI)): MySQL MCP Server is a Model Context Protocol server that enables secure interaction with MySQL databases. Prior to…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-15
date_modified: 2026-09-15
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-59971"
kev: false
cvss: 10
epss: 0.00418
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.4% , percentile 35: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 35% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes mysql-mcp-server (PyPI) < 0.4.2, fixed in 0.4.2 . Check your lockfile, including transitive dependencies.

## What it is

MySQL MCP Server is a Model Context Protocol server that enables secure interaction with MySQL databases. Prior to 0.4.2, setting MCPTRANSPORT=sse causes src/mysqlmcpserver/server.py to construct SseServerTransport without securitysettings or enablednsrebindingprotection, 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 executesql, 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.

## Affected packages

- PyPI `mysql-mcp-server` < 0.4.2 → fixed: 0.4.2

## Affected products (CVE record)

- designcomputer mysql_mcp_server: < 0.4.2

## Severity

- GitHub_M CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 10.0 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.42% probability of exploitation activity in the next 30 days; percentile 35.

## Sources

- [GitHub Advisory GHSA-rqfv-2mw9-78g2](https://github.com/advisories/GHSA-rqfv-2mw9-78g2)
- [CVE.org record CVE-2026-59971](https://www.cve.org/CVERecord?id=CVE-2026-59971)
- [NVD entry CVE-2026-59971](https://nvd.nist.gov/vuln/detail/CVE-2026-59971)
- [github.com](https://github.com/designcomputer/mysql_mcp_server/security/advisories/GHSA-rqfv-2mw9-78g2)
- [github.com](https://github.com/designcomputer/mysql_mcp_server/issues/92)
- [github.com](https://github.com/designcomputer/mysql_mcp_server/commit/a96549f4a4d65443fd6e9c7f2324fba9a5c80a82)
- [github.com](https://github.com/designcomputer/mysql_mcp_server/releases/tag/v0.4.2)

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Source page: https://erroneo.us/security/cve/CVE-2026-59971/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt