---
id: CVE-2026-103223
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 PostgreSQL message decoder reads the 4-byte message
  length field from the PostgreSQL wire protocol without any maximum validation
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 PostgreSQL message decoder reads the 4-byte message
  length field from the PostgreSQL wire protocol without any maximum validation.
  A mal…
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: '2026-10-15T09:17:15.853'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-103223'
references:
  - url: >-
      https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-hm2j-xp3c-jff2
    label: emo@eclipse.org
  - url: 'https://gitlab.eclipse.org/security/cve-assignment/-/work_items/354'
    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 PostgreSQL message decoder reads the 4-byte message length field from the PostgreSQL wire protocol without any maximum validation. A malicious, compromised, or man-in-the-middle PostgreSQL server can send a message header with the length field set to an extremely large value (up to Integer.MAX_VALUE), causing the decoder to accumulate subsequent TCP data into a composite buffer without bound, leading to unbounded memory allocation on the client and an out-of-memory crash. This occurs before authentication completes.



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

## Remediation

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