CVE-2026-22558: UniFi Network NoSQL Injection Vulnerability

CVE-2026-22558 Overview

An Authenticated NoSQL Injection vulnerability has been identified in UniFi Network Application that could allow a malicious actor with authenticated access to the network to escalate privileges. This vulnerability falls under CWE-943 (Improper Neutralization of Special Elements in Data Query Logic), indicating that the application fails to properly sanitize user-supplied input before incorporating it into NoSQL database queries.

NoSQL injection vulnerabilities occur when applications construct database queries using untrusted input without adequate validation or sanitization. In this case, an authenticated attacker could manipulate query logic to access unauthorized data or escalate their privileges within the UniFi Network Application environment.

Critical Impact

Authenticated attackers can exploit this NoSQL injection flaw to escalate privileges and potentially gain unauthorized access to sensitive network configuration data managed by UniFi Network Application.

Affected Products

• UniFi Network Application (specific affected versions not disclosed)

Discovery Timeline

• 2026-03-19 - CVE CVE-2026-22558 published to NVD
• 2026-03-19 - Last updated in NVD database

Technical Details for CVE-2026-22558

Vulnerability Analysis

This vulnerability stems from improper input validation in the UniFi Network Application's handling of user-supplied data when constructing NoSQL database queries. The UniFi Network Application utilizes MongoDB as its backend database, which is susceptible to injection attacks when query parameters are not properly sanitized.

The scope of this vulnerability extends beyond the vulnerable component itself, as indicated by the changed scope metric. This means successful exploitation could impact resources beyond the security scope of the vulnerable application, potentially allowing access to sensitive network infrastructure data managed by the UniFi controller.

The attack requires only low-level privileges to execute, and no user interaction is needed. An attacker with basic authenticated access to the UniFi Network Application could craft malicious input to manipulate NoSQL queries, bypassing authorization controls to access confidential information or escalate their privileges within the system.

Root Cause

The root cause of CVE-2026-22558 is the failure to properly neutralize special elements in data query logic (CWE-943). The UniFi Network Application does not adequately validate or sanitize user input before incorporating it into MongoDB queries. This allows attackers to inject NoSQL operators such as $gt, $ne, $where, or $regex that alter the intended query logic.

When user-controlled data is directly concatenated or passed into query objects without proper sanitization, attackers can modify the query structure to bypass authentication checks, extract sensitive data, or manipulate database operations in unintended ways.

Attack Vector

The attack is network-based and can be executed remotely by any authenticated user with access to the UniFi Network Application. The attacker would identify input fields or API endpoints that interact with the MongoDB database and inject malicious NoSQL operators.

Common NoSQL injection techniques applicable to this vulnerability include:

• Injecting comparison operators like $ne (not equal) to bypass equality checks
• Using $gt (greater than) or $lt (less than) to manipulate numeric comparisons
• Leveraging $regex for pattern-based data extraction
• Exploiting $where clauses to execute arbitrary JavaScript on the database server

The low attack complexity means no specialized conditions are required—any authenticated user with network access to the application can potentially exploit this flaw. For detailed technical information, refer to the UI Community Security Advisory.

Detection Methods for CVE-2026-22558

Indicators of Compromise

• Unusual API requests containing NoSQL operators such as $ne, $gt, $lt, $regex, or $where in request parameters
• Authentication logs showing privilege escalation events or unauthorized access to administrative functions
• MongoDB query logs revealing malformed or suspicious query patterns
• Unexpected changes to user roles or permissions within the UniFi Network Application

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block NoSQL injection patterns in HTTP requests
• Monitor UniFi Network Application logs for unusual API activity or repeated failed authorization attempts followed by successful access
• Deploy network intrusion detection systems (NIDS) with signatures for common NoSQL injection payloads
• Audit MongoDB query logs for queries containing suspicious operators or unexpected query structures

Monitoring Recommendations

• Enable verbose logging on the UniFi Network Application and MongoDB backend to capture detailed query information
• Set up alerts for privilege escalation events or changes to administrative user accounts
• Implement baseline monitoring for normal API usage patterns to detect anomalous behavior
• Regularly review access logs for authenticated users accessing resources outside their normal scope

How to Mitigate CVE-2026-22558

Immediate Actions Required

• Apply the security patch provided by Ubiquiti as referenced in their security advisory
• Review user accounts and privileges for any unauthorized changes or escalations
• Audit access logs for signs of exploitation attempts
• Restrict network access to the UniFi Network Application to trusted IP addresses where possible

Patch Information

Ubiquiti has released a security advisory addressing this vulnerability. Administrators should review the UI Community Security Advisory for specific patch versions and upgrade instructions. Ensure the UniFi Network Application is updated to the latest available version that addresses CVE-2026-22558.

Workarounds

• Implement network segmentation to limit access to the UniFi Network Application to authorized management networks only
• Deploy a reverse proxy or WAF in front of the UniFi Network Application with NoSQL injection detection rules enabled
• Review and restrict user privileges to the minimum necessary for their operational requirements
• Enable multi-factor authentication (MFA) for all administrative accounts to add an additional layer of protection

# Example: Restrict access to UniFi controller via iptables
# Allow access only from trusted management network
iptables -A INPUT -p tcp --dport 8443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 8443 -j DROP