---
id: CVE-2026-102469
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 DB2 client (vertx-db2-client) contains DRDA
  protocol handling code that deserializes User Defined Type (UDT) column data
  using a …
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 DB2 client (vertx-db2-client) contains DRDA
  protocol handling code that deserializes User Defined Type (UDT) column data
  using a …
severity: critical
cvss: 9.2
cvssVector: 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/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: '2026-10-15T09:17:15.573'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102469'
references:
  - url: >-
      https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-j4vf-w939-pgxf
    label: emo@eclipse.org
  - url: 'https://gitlab.eclipse.org/security/cve-assignment/-/work_items/347'
    label: emo@eclipse.org
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-10-15T08:58:33.103Z'
---

## 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 DB2 client (vertx-db2-client) contains DRDA protocol handling code that deserializes User Defined Type (UDT) column data using a bare ObjectInputStream.readObject() call with no ObjectInputFilter or class allowlist.



This code path is triggered when a DRDA server sends a result set with a column tagged as UDT (FDOCA protocol LID 0x50). However, DB2 does not support this type of UDT. The FDOCA 0x50 type is never sent by a legitimate DB2 server.



Nevertheless, a malicious or man-in-the-middle DRDA server could craft a response with a 0x50-tagged column, causing the client to deserialize arbitrary attacker-controlled bytes on the Vert.x event loop before any application code can inspect or reject the data. If a Java deserialization gadget chain is present on the application's classpath, this enables remote code execution. Without a gadget chain, denial of service is possible via crafted object graphs. TLS is disabled by default, making man-in-the-middle exploitation feasible.



The impacted component is io.vertx:vertx-db2-client.

## Remediation

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