CVE-2026-26186: Fleet Device Management SQL Injection

CVE-2026-26186 Overview

Fleet is an open source device management software platform used for managing and monitoring endpoints across organizations. A SQL injection vulnerability was discovered in versions prior to 4.80.1 that allows authenticated users to inject arbitrary SQL expressions via the order_key query parameter. This vulnerability arises from unsafe use of goqu.I() when constructing the ORDER BY clause, where specially crafted input can escape identifier quoting and be interpreted as executable SQL.

Critical Impact

Authenticated attackers can perform blind SQL injection attacks to disclose database information through conditional expressions affecting result ordering, potentially leading to data exfiltration and denial of service.

Affected Products

• Fleet Device Management Software versions prior to 4.80.1

Discovery Timeline

• 2026-02-26 - CVE CVE-2026-26186 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2026-26186

Vulnerability Analysis

This SQL injection vulnerability (CWE-89) exists in Fleet's query construction logic where user-supplied input for the order_key parameter is not properly sanitized before being incorporated into SQL queries. The vulnerability specifically manifests in the ORDER BY clause construction, where the application uses goqu.I() function to build dynamic column identifiers.

The unsafe handling of the order_key parameter allows attackers to escape the identifier quoting mechanism. While the injection point is within an ORDER BY context, which typically limits direct data extraction, skilled attackers can leverage blind SQL injection techniques to infer database contents by crafting expressions that conditionally affect query result ordering.

The vulnerability requires authentication to exploit, which limits the attack surface to users with valid credentials. However, the potential for database information disclosure and denial of service through resource-intensive queries makes this a significant security concern for Fleet deployments.

Root Cause

The root cause of this vulnerability lies in the improper use of the goqu.I() function when constructing dynamic SQL queries. The goqu library's identifier function is designed to safely quote column and table names, but when user input is passed directly to this function without validation, attackers can craft input that escapes the quoting mechanism.

The application failed to implement proper allow-listing or validation of the order_key parameter against a predefined set of acceptable column names, allowing arbitrary input to reach the SQL query construction logic.

Attack Vector

The attack is network-based and requires the attacker to be authenticated to the Fleet application. An attacker can exploit this vulnerability by sending specially crafted HTTP requests to the affected endpoint with malicious SQL expressions embedded in the order_key query parameter.

The exploitation technique involves blind SQL injection where the attacker crafts conditional SQL expressions that affect the ordering of query results. By observing changes in result ordering, the attacker can infer information about the database structure and contents bit by bit.

Additionally, attackers can construct computationally expensive SQL expressions that cause excessive database load, potentially leading to degraded performance or denial of service conditions. The advisory notes that no direct evidence of reliable data modification or stacked query execution was demonstrated, suggesting the vulnerability's impact is primarily limited to information disclosure and availability impacts.

Detection Methods for CVE-2026-26186

Indicators of Compromise

• Unusual or malformed values in the order_key query parameter in web server access logs
• HTTP requests containing SQL syntax characters (quotes, semicolons, comments) in sorting parameters
• Database query logs showing anomalous ORDER BY clauses with unexpected expressions
• Increased database query execution times without corresponding legitimate traffic increases

Detection Strategies

• Monitor web application logs for requests to affected endpoints containing suspicious order_key parameter values
• Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in query string parameters
• Review database slow query logs for queries with unusual ORDER BY expressions
• Deploy application-layer intrusion detection to identify SQL injection attempt patterns

Monitoring Recommendations

• Enable detailed request logging for the affected Fleet endpoints and review for anomalous parameter values
• Configure alerting for database performance degradation that may indicate SQL injection-based denial of service attempts
• Establish baseline metrics for normal API usage patterns to identify deviations indicative of exploitation
• Monitor authentication logs for unusual access patterns from authenticated users targeting the vulnerable endpoint

How to Mitigate CVE-2026-26186

Immediate Actions Required

• Upgrade Fleet to version 4.80.1 or later immediately to apply the security fix
• Restrict access to the affected endpoint to trusted roles only until patching is complete
• Implement strict allow-listing for any user-supplied sort or column parameters at the application or proxy layer
• Review access logs for evidence of exploitation attempts prior to patching

Patch Information

The vulnerability has been addressed in Fleet version 4.80.1. Organizations running Fleet should upgrade to this version or later to remediate the vulnerability. For detailed information about the fix, refer to the GitHub Security Advisory.

Workarounds

• If immediate upgrade is not possible, restrict access to the affected endpoint to trusted administrative roles only
• Implement strict allow-listing of permitted order_key values at the reverse proxy or API gateway layer
• Deploy WAF rules to block requests containing SQL injection patterns in query parameters
• Consider temporarily disabling sorting functionality on affected endpoints until patching can be completed

# Example: Nginx location block to restrict order_key values
# Add to Fleet reverse proxy configuration
location /api/v1/fleet/ {
    # Allow only alphanumeric characters and underscores in order_key
    if ($arg_order_key ~* "[^a-zA-Z0-9_]") {
        return 400;
    }
    proxy_pass http://fleet_backend;
}