External risk intelligence

Amazon Neptune Gremlin Component Deserialization Vulnerability Allows Code Execution

CVE advisorySeverity: CRITICAL (CVSS 9.4)

CVE-2026-110812

Amazon Neptune is a managed graph database service typically deployed within private virtual networks. Access to the database engine and its data import components is generally restricted to internal applications or authorized users via secure database connections, rather than being directly exposed to the public internet.

Deserialization

Halo Surface Signal: 2 out of 5 — less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in the Amazon Neptune graph data import component that could allow an authenticated user to execute arbitrary code and access internal service credentials. This issue affects the Gremlin graph data import functionality within the Neptune engine.

Untrusted data imports can be exploited.
It impacts core data handling and credential security.
Confirming relevance and exposure is the key concern.

Attack Path

How an attacker could exploit the issue

An attacker with standard database permissions could exploit this vulnerability by submitting untrusted data during the Gremlin graph import process. This could allow them to execute arbitrary code and steal internal service credentials.

Requires authenticated access.
Triggered by importing untrusted data.
Leads to code execution and credential theft.

Live Threat

Current exploitation, exposure, and threat context

An authenticated remote actor with standard database permissions could execute arbitrary code and access internal service credentials within the Gremlin graph data import component of Amazon Neptune. This could occur when the component deserializes untrusted data, potentially leading to unauthorized access and control over the database and its associated services.

Internal service credentials and database access.
Deserialization of untrusted data during import.
Unauthorized code execution and data compromise.

Operational Fix

Recommended remediation, mitigation, and detection steps

To address this deserialization vulnerability in Amazon Neptune, the platform or infrastructure teams managing the Neptune engine are likely responsible for the initial investigation. The first practical step involves identifying all Neptune instances, confirming their network accessibility, and assessing their business criticality to prioritize remediation efforts.

Own the Neptune engine update.
Verify Neptune instance exposure.
Plan and execute engine upgrade.

Supplementary metadata

CVSS vector

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Frequently asked questions

What is Amazon Neptune?

Amazon Neptune is a fully managed, high-performance graph database service. It is designed to store and navigate highly connected data sets, such as social networks or recommendation engines. This specific issue involves the Gremlin component, which is a graph traversal language used to query and manipulate the data stored within the engine.

What does CVE-2026-110812 mean by deserialization?

Deserialization is the process of turning stored data back into an active software object. The weakness, classified as CWE-502, occurs when a system trusts incoming data without enough checks. In this case, the Gremlin import component may process malicious input, allowing an attacker to manipulate the object creation process to execute unauthorized code.

How is this vulnerability triggered?

An attacker must have existing, authenticated database permissions to trigger this flaw. By submitting specifically crafted, untrusted data during the Gremlin graph import process, they can exploit the deserialization mechanism. Simply querying or reading existing data does not initiate the risky import code path.

Is my Neptune database at risk?

Halo Surface Signal indicates that this is unlikely for most users, as Amazon Neptune is typically deployed within private virtual networks rather than being public-facing. The primary concern applies to environments where database connections might be accessible to compromised internal applications or unauthorized actors who have already gained valid database credentials.

How do I respond to this vulnerability?

The most effective response is to update your Amazon Neptune engine to version 1.5.0.0, or apply the specific backports for versions 1.4.8.x and 1.4.7.x. Prioritize this by identifying all active Neptune instances in your environment, verifying who has access to them, and scheduling the engine upgrade through your standard maintenance window.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.