---
id: "CVE-2026-101621"
kind: "vulnerability"
aliases: ["CVE-2026-101621"]
title: "MySQL Server: InnoDB flaw lets a privileged user crash the server"
severity: "medium"
cvss: 4.9
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["database", "mysql", "package", "self-hosted"]
not_affected_if: ["no-privileged-accounts-exposed", "patched-version"]
published_at: "2026-10-20T22:18:16+00:00"
first_seen_at: "2026-10-23T21:57:22+00:00"
updated_at: "2026-10-25T04:31:35+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-101621", "first_seen_at": "2026-10-23T21:57:22+00:00"}]
---

# MySQL Server: InnoDB flaw lets a privileged user crash the server

A flaw in the InnoDB storage engine of MySQL Server and MySQL Cluster can be triggered over the network by a highly privileged account. A successful attack hangs or repeatedly crashes the database, denying service to everything that depends on it.

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

## How to check

- Run `SELECT VERSION();` on the MySQL server and compare against the affected ranges: 8.4.0 to 8.4.12, 9.7.0 to 9.7.3, 26.7.0 to 26.7.1, and MySQL Cluster 8.0.0 to 8.0.49.
- Check whether the deployment is MySQL Cluster (NDB) or a standalone server; both are listed.

## Fix

- Upgrade MySQL Server or MySQL Cluster to a release outside the affected ranges; the sources do not name the exact fixed version, so check Oracle's Critical Patch Update notes.

## Timeline

- 2026-10-23T21:57:22+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-101621

## From the sources

Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: InnoDB).  Supported versions that are affected are MySQL Server: 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster: 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3 and  26.7.0-26.7.1. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server, MySQL Cluster.  Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server, MySQL Cluster. CVSS 3.1 Base Score 4.9 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

---

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