---
id: CVE-2026-102466
title: >-
  In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9]
  or [5.2.0, 5.2.0], the Vert.x MySQL client (vertx-mysql-client) pre-allocates
  an array for column definitions based on a server-declared column count with
  no u…
summary: >-
  In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9]
  or [5.2.0, 5.2.0], the Vert.x MySQL client (vertx-mysql-client) pre-allocates
  an array for column definitions based on a server-declared column count with
  no u…
severity: high
cvss: 8.2
cvssVector: 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'
vendor: Eclipse Foundation
product: Eclipse Vert.x
affected:
  - eclipse_vert.x >= 4.0.0 <= 4.5.34
  - eclipse_vert.x >= 5.0.0 <= 5.0.12
  - eclipse_vert.x >= 5.1.0 <= 5.1.9
  - eclipse_vert.x 5.2.0
published: '2026-10-15'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T09:17:15.427'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102466'
references:
  - url: >-
      https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-9jxp-x3fr-ffqh
    label: emo@eclipse.org
  - url: 'https://gitlab.eclipse.org/security/cve-assignment/-/work_items/342'
    label: emo@eclipse.org
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-10-15T08:58:33.101Z'
---

## Overview

In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the Vert.x MySQL client (vertx-mysql-client) pre-allocates an array for column definitions based on a server-declared column count with no upper-bound validation. A malicious or compromised MySQL server, or an attacker with man-in-the-middle positioning, can send a crafted result set packet with an extremely large column count, causing the client to attempt a massive heap allocation. The resulting OutOfMemoryError crashes the Netty event loop thread, causing a complete denial of service for all connections and verticles in the Vert.x application.



The impacted component is io.vertx:vertx-mysql-client.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.