---
id: "CVE-2026-101720"
kind: "vulnerability"
aliases: ["CVE-2026-101720"]
title: "MySQL Server: connection handling flaw allows unauthorized data changes over network"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["databases", "mysql", "mysql-cluster", "runtime", "self-hosted"]
not_affected_if: ["default-config"]
published_at: "2026-10-20T22:18:26+00:00"
first_seen_at: "2026-10-23T21:57:23+00:00"
updated_at: "2026-10-25T04:23:11+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-101720", "first_seen_at": "2026-10-23T21:57:23+00:00"}]
---

# MySQL Server: connection handling flaw allows unauthorized data changes over network

A flaw in MySQL Server and MySQL Cluster connection handling, affecting versions 26.7.0 through 26.7.1, lets an unauthenticated attacker with network access modify data. Successful attacks allow unauthorized update, insert or delete access to some accessible data.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `mysqld --version` on each database host and compare against the affected range `26.7.0` to `26.7.1`
- Check whether MySQL Server or MySQL Cluster is reachable from networks beyond the application tier

## Fix

- Upgrade MySQL Server and MySQL Cluster to a release newer than `26.7.1` once Oracle publishes the fixed version (unknown in the sources)
- Restrict network access to the MySQL port until patched

## Timeline

- 2026-10-23T21:57:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-101720

## From the sources

Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: Server: Connection Handling).  Supported versions that are affected are MySQL Server: 26.7.0-26.7.1; MySQL Cluster: 26.7.0-26.7.1. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise MySQL Server, MySQL Cluster.  Successful attacks of this vulnerability can result in  unauthorized update, insert or delete access to some of MySQL Server, MySQL Cluster accessible data. CVSS 3.1 Base Score 5.3 (Integrity impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N).

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_