CVE-2026-103224

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-15 · updated 2026-10-20
Weakness: CWE-789

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 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.

Affected products

Eclipse Foundation Eclipse Vert.x: from 4.5.0 before 4.5.35; from 5.0.0 before 5.1.10; 5.2.0 — fixed in 4.5.35, 5.1.10

How to fix

Upgrade to a fixed version: Eclipse Foundation Eclipse Vert.x 4.5.35, 5.1.10. Check the vendor advisory for mitigations.

References

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