External risk intelligence

Marten SQL Injection Vulnerability in Full-Text Search APIs.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-45288

Marten is a database library used within .NET applications. While it can be part of an internet-facing web application, the vulnerability requires specific code implementation where user-supplied input is passed to a full-text search API parameter. Public exposure depends entirely on the developer's application design rather than the library being an edge or gateway service by default.

SQL Injection

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A security flaw exists in the Marten database library, specifically within its full-text search functions. This vulnerability could allow an attacker to inject malicious SQL commands if untrusted input is processed through these functions, potentially leading to unauthorized access or manipulation of data.

  • Database search function vulnerable to code injection.
  • Critical vulnerability impacts data integrity and access.
  • Confirm exposure; assess impact on affected applications.

Attack Path

How an attacker could exploit the issue

An attacker can target Marten, a .NET database library, by sending specially crafted input to its full-text search features. Because the application does not properly check user-supplied data before using it in database queries, an attacker can manipulate these queries to execute arbitrary SQL commands. This could allow an attacker to gain unauthorized access to, modify, or delete sensitive data within the database.

  • No authentication or special access required.
  • User input sent to full-text search APIs.
  • Leads to unauthorized data access or modification.

Live Threat

Current exploitation, exposure, and threat context

In Marten, when full-text search APIs are exposed to untrusted input without proper validation, an attacker could inject malicious SQL commands. This could potentially lead to unauthorized access, modification, or deletion of sensitive data stored within the Marten database, depending on the application's implementation.

  • Database data and integrity at risk.
  • SQL injection via search queries.
  • Data compromise or system disruption.

Operational Fix

Recommended remediation, mitigation, and detection steps

Application owners and platform teams are likely responsible for addressing this SQL injection vulnerability in Marten, as it affects a .NET database library. The first step is to identify all applications using Marten, confirm which instances are exposed to untrusted input via the affected full-text search APIs, and then prioritize remediation based on risk and business criticality.

  • Application owners should own the issue.
  • Verify application exposure via full-text search.
  • Plan remediation during a maintenance window.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is the Marten library?

Marten is a specialized database library for .NET applications that functions as a transactional document database and event store, built on top of PostgreSQL. Developers use it to manage complex data structures and event sourcing within their software, effectively bridging their .NET code with the powerful relational capabilities of a Postgres backend.

How does CVE-2026-45288 cause a SQL injection?

This vulnerability is classified as CWE-89, or Improper Neutralization of Special Elements used in an SQL Command. In affected Marten versions, the full-text search API incorrectly handles the 'regConfig' parameter. By embedding this input directly into SQL statements without validation, the library allows an attacker to break out of the intended query and execute unauthorized commands against the database.

Do I need to worry if my search input is sanitized?

Not necessarily. The flaw specifically involves the library's internal handling of the 'regConfig' parameter. If your application code does not pass untrusted user input into this specific configuration parameter, you are not triggering this vulnerability. The risk only manifests when you allow external users to control the values processed by Marten's full-text search functions.

Is my application at risk from the internet?

According to Halo Surface Signal, this depends on your design. Marten is a library, not a standalone gateway. Your risk level is determined by whether your application exposes its search features to the public web. If you have a web-facing tool that allows users to perform full-text searches using this library, your application is a potential pathway for attackers to reach the underlying database.

When should I update Marten to fix this?

You should plan to update to version 8.36.1 or newer as soon as possible. Because this issue allows for potential data manipulation or unauthorized access, verify which of your services utilize Marten's full-text search capabilities and schedule an update for those specific components during your next maintenance window to ensure the library correctly handles search parameters.

References