CVSS 8.2 (high) ยท published 2026-10-15
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.
Affected products (NVD): eclipse vert.x
Fixed in (NVD): 4.5.35, 5.1.10
Weakness: CWE-789
Source: NVD CVE-2026-102466
Connect an AI agent to the Fixlane MCP server or ask the Telegram bot to check what you have installed against incidents with a verified fixed version.