---
title: "CVE-2026-103223: Eclipse Vert.x - Denial of Service"
description: "Eclipse Vert.x 4.0.0 to 4.5.34, 5.0.0 to 5.0.12, 5.1.0 to 5.1.9, and 5.2.0 contains an out-of-memory vulnerability caused by lack of maximum validation on PostgreSQL message length in io.vertx:vertx-pg-client, letting malicious or man-in-the-middle PostgreSQL servers cause unbounded memory allocation, exploit requires connection to a malicious PostgreSQL server."
url: https://panop.io/threat-heartbeat/CVE-2026-103223/
---

# CVE-2026-103223 Eclipse Vert.x - Denial of Service

Eclipse Vert.x 4.0.0 to 4.5.34, 5.0.0 to 5.0.12, 5.1.0 to 5.1.9, and 5.2.0 contains an out-of-memory vulnerability caused by lack of maximum validation on PostgreSQL message length in io.vertx:vertx-pg-client, letting malicious or man-in-the-middle PostgreSQL servers cause unbounded memory allocation, exploit requires connection to a malicious PostgreSQL server.

CVSS base score 8.2 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-103223)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Published

15 October 2026

Updated

15 October 2026

Weakness

[CWE-789](https://cwe.mitre.org/data/definitions/789.html)

## Vendor fix

Update to the latest version beyond 5.2.0 where this issue is fixed.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-103223](https://nvd.nist.gov/vuln/detail/CVE-2026-103223)
- [https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-hm2j-xp3c-jff2](https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-hm2j-xp3c-jff2)
- [https://gitlab.eclipse.org/security/cve-assignment/-/work\_items/354](https://gitlab.eclipse.org/security/cve-assignment/-/work_items/354)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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