Eclipse Vert.x MySQL client: Memory exhaustion via unbounded packet reassembly
Summary
The MySQL client library vertx-mysql-client in Eclipse Vert.x can be driven to exhaust memory before authentication completes. A malicious, compromised or man-in-the-middle MySQL server can send a continuous stream of maximum-length packets, causing unbounded direct-memory allocation and an OutOfMemory crash of the client application. The attack requires that the application connects to such a server or that an attacker sits in a man-in-the-middle position on that connection. The impact is limited to availability.
Affected
- Eclipse Vert.x 4.0.0 to 4.5.34
- Eclipse Vert.x 5.0.0 to 5.0.12
- Eclipse Vert.x 5.1.0 to 5.1.9
- Eclipse Vert.x 5.2.0
Package: io.vertx:vertx-mysql-client. The vendor advisory lists the ranges slightly differently (>=5.0.0 to <=5.1.8, 5.2.0 and <=4.5.34).
Fixed in
- 4.5.35
- 5.1.10
- 5.2.1
- 5.0.x: Unknown. The vendor advisory lists no fixed 5.0.x release.
Workaround
Unknown. The vendor advisory lists no workaround. Until patched, restrict the database network path, use TLS with server certificate verification and set memory limits for containers and Java processes. These measures are general recommendations, not vendor advice.
Exploitation
- No known exploitation in the wild.
- No public proof-of-concept known. VulDB lists no available exploit.
- CISA SSVC: exploitation none, not automatable.
Our recommendation
- Identify applications that use io.vertx:vertx-mysql-client, including bundled downstream products, using your Java SBOM.
- Update to 4.5.35, 5.1.10 or 5.2.1 where applicable.
- For 5.0.x, confirm the fix status with the Vert.x project before planning.
- Use TLS with certificate verification for database connections and restrict database network access.
- Set memory limits and monitor for OutOfMemory errors.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Security Advisory GHSA-75hv-9xj3-3cr8 github.com
- Eclipse CVE work item #353 gitlab.eclipse.org
- Fix pull request #1734 (vertx-sql-client) github.com
- NVD record via Vulners vulners.com
- VulDB entry 420548 vuldb.com
- OpenCVE CVE-2026-103224 app.opencve.io
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 16:07.
Original description (NVD)
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 MySQL message decoder aggregates inbound multi-packet payloads into a composite direct-memory buffer without any cumulative size limit. A malicious, compromised, or man-in-the-middle MySQL server can send a continuous stream of packets with the maximum payload length (0xFFFFFF), preventing the end-of-message condition from being reached, causing unbounded direct-memory allocation on the client and leading to an out-of-memory crash. This occurs before authentication completes. The impacted component is io.vertx:vertx-mysql-client.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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