Bug 2553092 (CVE-2026-102466)

Summary: CVE-2026-102466 io.vertx/vertx-mysql-client: vertx-mysql-client: Denial of Service via unvalidated column count memory allocation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: ant, cescoffi, fmongiar, gsmet, jmartisk, manderse, olubyans, ozzy, pjindal, rguimara, sbiarozk, varjain
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Eclipse Vert.x MySQL client, which can lead to a Denial of Service (DoS). A malicious database server or an attacker positioned on the network can send a crafted result set containing an excessively large column count. Because the client pre-allocates memory for column definitions without validating upper bounds, this triggers an excessive memory allocation that crashes the processing thread and disrupts active connections.
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Description OSIDB Bzimport 2026-10-15 08:32:17 UTC 
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.