# CVE-2026-103224: Eclipse Vert.x MySQL client unbounded memory buffer in message decoder

Source: https://junglewise.ai/threats/cve-2026-103224-in-eclipse-vert-x-versions-4-0-0-4-5-34-or-5-0-0-5-0-12-or-5-1-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-15. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-103224 · Severity: info · Published 2026-10-15

Eclipse Vert.x's MySQL client library fails to enforce size limits when reassembling multi-packet messages from a database server. An attacker who controls or intercepts the MySQL server connection can send specially crafted packets that cause the client to allocate unbounded amounts of memory, crashing the application with an out-of-memory error. This attack requires no authentication and can occur before the client even logs in.

Vendors: [Eclipse](https://junglewise.ai/threats/vendors/eclipse).

## Quick answers

**Is CVE-2026-103224 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-103224 being exploited in the wild.

**How severe is CVE-2026-103224?** Informational severity, published 15 October 2026.

**Which products and versions are affected?** Eclipse Vert.x MySQL client 4.0.0–4.5.34, 5.0.0–5.0.12, 5.1.0–5.1.9, 5.2.0.

**Is there a fix for CVE-2026-103224?** Yes: fixed in Vert.x MySQL client 4.5.35, 5.1.10, 5.2.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-103224 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-103224?** Check whether you run Eclipse Vert.x MySQL client at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Vert.x MySQL client 4.5.35, 5.1.10, 5.2.1

## Technical details

The MySQL message decoder in vertx-mysql-client aggregates inbound multi-packet payloads into a composite direct-memory buffer without enforcing cumulative size limits. An attacker controlling a malicious or compromised MySQL server can send a continuous stream of maximum-length packets (0xFFFFFF bytes each) to prevent the end-of-message condition, causing unbounded heap allocation and triggering an out-of-memory crash before authentication completes. The vulnerability affects multiple versions across the 4.x and 5.x release lines.

## Affected products

- Eclipse Vert.x MySQL client 4.0.0–4.5.34, 5.0.0–5.0.12, 5.1.0–5.1.9, 5.2.0

## Timeline

- 2026-10-07: disclosed
- 2026-10-15: advisory

## References

- [https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-75hv-9xj3-3cr8](https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-75hv-9xj3-3cr8)
- [https://gitlab.eclipse.org/security/cve-assignment/-/work_items/353](https://gitlab.eclipse.org/security/cve-assignment/-/work_items/353)

## Related threats

- [Eclipse Vert.x MySQL client denial of service via uncapped column count](https://junglewise.ai/threats/cve-2026-102466-in-eclipse-vert-x-versions-4-0-0-4-5-34-or-5-0-0-5-0-12-or-5-1-0)