CVE-2026-103223

MEDIUMCVSS 5.9/10EPSS 0.32%

Last modified

CVE-2026-103223 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. 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 PostgreSQL message decoder reads the 4-byte message length field from the PostgreSQL wire protocol without any maximum validation. A malicious, compromised, or man-in-the-middle PostgreSQL server can send a message header with the length field set to an extremely large value (up to Integer.MAX_VALUE), causing the decoder to accumulate subsequent TCP data into a composite buffer without bound, leading to unbounded memory allocation on the client and an out-of-memory crash. EPSS estimates a 0.32% chance of exploitation in the next 30 days.

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 PostgreSQL message decoder reads the 4-byte message length field from the PostgreSQL wire protocol without any maximum validation. A malicious, compromised, or man-in-the-middle PostgreSQL server can send a message header with the length field set to an extremely large value (up to Integer.MAX_VALUE), causing the decoder to accumulate subsequent TCP data into a composite buffer without bound, leading to unbounded memory allocation on the client and an out-of-memory crash. This occurs before authentication completes. The impacted component is io.vertx:vertx-pg-client.

Metrics

Weakness Enumeration

Affected Software

VendorProductVersions
EclipseVert.X>= 4.5.0, < 4.5.35
EclipseVert.X>= 5.0.0, < 5.1.10
EclipseVert.X5.2.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-103223?
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 PostgreSQL message decoder reads the 4-byte message length field from the PostgreSQL wire protocol without any maximum validation. A malicious, compromised, or man-in-the-middle PostgreSQL server can send a message header with the length field set to an extremely large value (up to Integer.MAX_VALUE), causing the decoder to accumulate subsequent TCP data into a composite buffer without bound, leading to unbounded memory allocation on the client and an out-of-memory crash. This occurs before authentication completes. The impacted component is io.vertx:vertx-pg-client.
How severe is CVE-2026-103223?
CVE-2026-103223 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.
How do I fix CVE-2026-103223?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST