CVE-2026-23597: HPE Aruba 5G Core Information Disclosure

CVE-2026-23597 Overview

CVE-2026-23597 is an Information Disclosure vulnerability affecting the API error handling mechanism in HPE Aruba Networking 5G Core server. The vulnerability allows an unauthenticated remote attacker on an adjacent network to obtain sensitive information through improper error handling responses from the API.

Successful exploitation could allow an attacker to access details such as user accounts, roles, and system configuration, as well as to gain insight into internal services and workflows. This information leakage significantly increases the risk of unauthorized access and elevated privileges when combined with other vulnerabilities.

Critical Impact

Unauthenticated attackers on the adjacent network can extract sensitive system configuration, user account details, and internal workflow information through verbose API error responses.

Affected Products

• HPE Aruba Networking 5G Core Server

Discovery Timeline

• 2026-02-17 - CVE-2026-23597 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2026-23597

Vulnerability Analysis

This vulnerability is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor). The flaw exists in how the HPE Aruba Networking 5G Core server API handles and responds to error conditions.

When API requests encounter error states, the server returns overly verbose error messages that inadvertently disclose sensitive internal information. This information exposure can reveal critical details about the system's architecture, including user accounts, role assignments, and system configuration parameters.

The vulnerability requires adjacent network access to exploit, meaning the attacker must be positioned on the same local network segment or have equivalent network proximity to the target system. No authentication is required to trigger the vulnerable error handling, and no user interaction is needed.

Root Cause

The root cause of this vulnerability lies in improper error handling implementation within the 5G Core server API. The API fails to sanitize or suppress sensitive information from error responses before returning them to clients.

When the API encounters exceptions or invalid requests, the error handling routines include detailed diagnostic information that was likely intended for debugging purposes. This diagnostic data includes internal system details that should never be exposed to unauthenticated clients, such as user enumeration data, role hierarchies, service endpoints, and configuration parameters.

Attack Vector

The attack vector requires the attacker to have adjacent network access to the vulnerable HPE Aruba Networking 5G Core server. From this position, the attacker can send crafted API requests designed to trigger error conditions.

By analyzing the verbose error responses returned by the API, the attacker can systematically extract sensitive information about the target environment. This reconnaissance data can then be leveraged to plan further attacks, potentially combining this information disclosure with other vulnerabilities to achieve unauthorized access or privilege escalation.

The vulnerability mechanism involves sending malformed or unexpected API requests to trigger error responses. The API's error handling routine then returns detailed diagnostic information that reveals internal system details. For technical details and specific affected versions, refer to the HPE Security Advisory.

Detection Methods for CVE-2026-23597

Indicators of Compromise

• Unusual volume of API requests from a single source, particularly malformed requests designed to trigger errors
• Repeated API error responses being sent to unauthenticated clients
• Network traffic patterns showing systematic probing of API endpoints
• Logs indicating failed API authentication attempts followed by successful information gathering

Detection Strategies

• Monitor API access logs for patterns of requests that consistently generate error responses
• Implement anomaly detection for unusual query patterns targeting error-prone endpoints
• Deploy network-based intrusion detection rules to identify reconnaissance activity against the 5G Core API
• Enable verbose logging on API gateways to capture and correlate suspicious request sequences

Monitoring Recommendations

• Configure SIEM rules to alert on high volumes of API error responses to unauthenticated sources
• Implement rate limiting and throttling on API endpoints to detect and mitigate enumeration attempts
• Monitor network traffic from adjacent network segments for unusual API interaction patterns
• Establish baseline API usage metrics to identify anomalous behavior indicative of exploitation attempts

How to Mitigate CVE-2026-23597

Immediate Actions Required

• Review and apply the latest security patches from HPE Aruba Networking as referenced in the security advisory
• Implement network segmentation to restrict access to the 5G Core server API from untrusted network segments
• Enable additional authentication requirements for API access where possible
• Review API error handling configurations to suppress verbose diagnostic information

Patch Information

HPE has released a security advisory addressing this vulnerability. Organizations should consult the HPE Security Advisory for specific patch information and affected version details.

Apply vendor-provided patches as soon as they become available following your organization's change management procedures. Prioritize patching based on the exposure level of your 5G Core infrastructure.

Workarounds

• Implement strict network access controls to limit which systems can communicate with the 5G Core server API
• Deploy a Web Application Firewall (WAF) or API gateway to filter and sanitize error responses before they reach clients
• Enable API request validation at the network perimeter to block malformed requests before they reach the vulnerable component
• Consider implementing IP allowlisting for API access until patches can be applied

# Example network access control configuration
# Restrict API access to authorized management networks only
# Consult your specific network infrastructure documentation for implementation details

# Example: iptables rule to restrict API port access
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP