CVE-2026-102466 Eclipse Foundation CVE debrief

Who should care

Developers and administrators using the affected Vert.x MySQL client versions should assess their exposure and prioritize patching or mitigation to prevent potential DoS attacks. This requires immediate attention from developers and administrators using the affected Vert.x MySQL client versions, especially those managing Vert.x applications with MySQL client dependencies.

Why it matters

CVE-2026-102466 is a high-severity vulnerability in the Eclipse Vert.x MySQL client that can lead to a denial-of-service (DoS) attack. Defenders should prioritize patching or mitigating this vulnerability to prevent potential DoS attacks. This requires immediate attention from developers and administrators using the affected Vert.x MySQL client versions.

• Potential denial-of-service (DoS) attacks against Vert.x applications using the MySQL client
• Complete denial of service for all connections and verticles in the Vert.x application
• Possible data loss or corruption due to forced application restarts

Technical summary

The Eclipse Vert.x MySQL client is vulnerable to a DoS attack due to a lack of upper-bound validation on the server-declared column count. This can lead to a massive heap allocation and subsequent OutOfMemoryError, causing a complete denial of service for all connections and verticles in the Vert.x application. The vulnerability exists in 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] of the Vert.x MySQL client (vertx-mysql-client). 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.

Defensive priority

Defenders should prioritize patching or mitigating this vulnerability to prevent potential DoS attacks. This requires immediate attention from developers and administrators using the affected Vert.x MySQL client versions.

Recommended defensive actions

• Patch or upgrade to a non-vulnerable version of the Vert.x MySQL client
• Implement network monitoring to detect potential exploitation attempts
• Consider using compensating controls, such as rate limiting or IP blocking
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD vulnerability detail provide information on the vulnerability. Additional context from source references may be necessary for a comprehensive understanding, but evidence is limited. Defenders should verify affected scope and vendor guidance with official advisories. Limited source information may constrain further detail.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.