CVE-2026-102466 Denial of service in Eclipse Vert.x

High 8.2 Published 15 Oct 2026 Updated 15 Oct 2026

A malicious MySQL server can cause a denial of service in Vert.x applications by sending a crafted packet with an excessive column count, triggering an OutOfMemoryError.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-102466?

CVE-2026-102466 is a high-severity denial of service vulnerability in Eclipse Vert.x, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-789

Which versions are affected by CVE-2026-102466?

It affects 1 product.

Products include Eclipse Vert.x.

How do I fix CVE-2026-102466?

No fix has been published for CVE-2026-102466 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-102466 being exploited?

There is no known exploitation of CVE-2026-102466 in the wild and no public exploit code.

Sources

Also known as GHSA-9jxp-x3fr-ffqh, GHSA-wpjj-864q-ggc9.