# CVE-2026-102463: Eclipse Vert.x PostgreSQL client unbounded array allocation denial of service

Source: https://junglewise.ai/threats/cve-2026-102463-in-eclipse-vert-x-versions-4-0-0-4-5-34-or-5-0-0-5-0-12-or-5-1-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-15. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-102463 · Severity: medium · CVSS 5.9 · Published 2026-10-15

Eclipse Vert.x's PostgreSQL client library handles database connections for Java applications. A malicious or compromised PostgreSQL server can send a specially crafted message that causes the client to attempt an enormous memory allocation, crashing the application. An attacker with network access to an unencrypted database connection can trigger a denial of service without authentication.

Technologies: [Eclipse Vert.X](https://junglewise.ai/threats/technologies/eclipse-vert-x). Vendors: [Eclipse](https://junglewise.ai/threats/vendors/eclipse), [Eclipse Foundation](https://junglewise.ai/threats/vendors/eclipse-foundation).

## Quick answers

**Is CVE-2026-102463 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-102463 being exploited in the wild.

**How severe is CVE-2026-102463?** Medium severity, with a CVSS score of 5.9, published 15 October 2026.

**Which products and versions are affected?** Eclipse Foundation Vert.x PostgreSQL Client 4.0.0 through 4.5.34, 5.0.0 through 5.0.12, 5.1.0 through 5.1.9, 5.2.0.

**Is there a fix for CVE-2026-102463?** Yes: fixed in 4.5.35, 5.1.10, 5.2.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-102463 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-102463?** Check whether you run Eclipse Vert.X or Eclipse Foundation Vert.x PostgreSQL Client at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 4.5.35, 5.1.10, 5.2.1

## Technical details

The binary array decoder in vertx-pg-client (DataTypeCodec.binaryDecodeArray) accepts a 32-bit dimension count from the server without validation or bounds-checking, leading to unbounded array allocation. A network attacker (malicious database server or on-path interceptor on an unencrypted connection) can send a crafted DataRow message with an excessively large dimension value, causing the client to attempt a multi-gigabyte heap allocation and crash with OutOfMemoryError.

## Affected products

- Eclipse Foundation Vert.x PostgreSQL Client 4.0.0 through 4.5.34, 5.0.0 through 5.0.12, 5.1.0 through 5.1.9, 5.2.0

## Timeline

- 2026-10-07: disclosed: GitHub security advisory published
- 2026-10-15: advisory: CVE-2026-102463 published on NVD

## References

- [https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-xqmh-8fhj-48fp](https://github.com/eclipse-vertx/vertx-sql-client/security/advisories/GHSA-xqmh-8fhj-48fp)
- [https://gitlab.eclipse.org/security/cve-assignment/-/work_items/345](https://gitlab.eclipse.org/security/cve-assignment/-/work_items/345)

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