CVE-2026-0689: ExtremeCloud IQ Information Disclosure Flaw

CVE-2026-0689 Overview

A sensitive data exposure vulnerability exists in ExtremeCloud IQ – Site Engine (XIQ‑SE) before version 26.2.10. The flaw resides in the NAC administration interface, where an authenticated NAC administrator can retrieve masked sensitive parameters from HTTP responses. Although credentials appear redacted in the user interface, the application returns the underlying credential values in the HTTP response body, enabling an authorized administrator to recover stored secrets that may exceed their intended access level.

This vulnerability was responsibly reported by the Lockheed Martin Red Team through coordinated disclosure with Extreme Networks.

Critical Impact

Authenticated administrators can extract plaintext credentials and sensitive secrets from HTTP responses despite UI-level masking, potentially enabling lateral movement or privilege escalation beyond their intended access scope.

Affected Products

• ExtremeCloud IQ – Site Engine (XIQ‑SE) versions prior to 26.2.10
• NAC administration interface components

Discovery Timeline

• 2026-03-02 - CVE-2026-0689 published to NVD
• 2026-03-02 - Last updated in NVD database

Technical Details for CVE-2026-0689

Vulnerability Analysis

This vulnerability falls under CWE-522 (Insufficiently Protected Credentials), a category of weaknesses where credential storage and transmission mechanisms fail to adequately protect sensitive authentication data. In the case of CVE-2026-0689, the XIQ-SE NAC administration interface implements visual masking of credentials at the presentation layer but fails to enforce equivalent protection at the data transport layer.

When an authenticated administrator accesses configuration pages containing stored credentials, the web application properly displays masked values (such as asterisks) in the user interface. However, the underlying HTTP response transmitted from the server contains the actual credential values in plaintext or an easily reversible format. This architectural flaw allows any user with network access to intercept responses or simply inspect browser developer tools to extract sensitive secrets.

The impact is particularly significant in enterprise network management contexts, as XIQ-SE stores credentials for network device authentication, RADIUS servers, LDAP directories, and other infrastructure components. Extraction of these credentials could enable an attacker to compromise additional network infrastructure beyond the XIQ-SE platform itself.

Root Cause

The root cause stems from improper separation between data access control and presentation layer masking. The application architecture sends complete credential data to the client-side UI, which then performs masking locally rather than receiving pre-sanitized data from the server. This "security through obscurity" approach at the UI level provides no actual protection against determined actors who can inspect HTTP traffic or browser responses.

The server-side API endpoints responsible for returning configuration data lack filtering logic to redact sensitive credential fields before transmission, relying entirely on client-side presentation to protect these values.

Attack Vector

Exploitation requires network-level access and valid NAC administrator credentials. An attacker with authenticated access to the XIQ-SE web interface can extract hidden credentials through the following approach:

1. The attacker authenticates to the XIQ-SE NAC administration interface with valid administrator credentials
2. The attacker navigates to configuration pages that display stored credentials (shown as masked values in the UI)
3. Using browser developer tools or an intercepting proxy, the attacker inspects the raw HTTP response body
4. The response contains unmasked credential values that were intended to remain hidden
5. The attacker extracts these credentials for use against other systems such as RADIUS servers, LDAP directories, or network devices

This attack requires no specialized tools beyond a web browser with developer tools enabled. The vulnerability is particularly concerning in multi-administrator environments where credential access should be compartmentalized based on administrative roles.

Detection Methods for CVE-2026-0689

Indicators of Compromise

• Unusual patterns of HTTP response inspection or developer tools usage by administrator accounts
• Repeated access to credential configuration pages without corresponding configuration changes
• Unauthorized access to network devices, RADIUS servers, or LDAP directories using credentials stored in XIQ-SE
• Evidence of credential harvesting from network traffic captures targeting the XIQ-SE management interface

Detection Strategies

• Monitor XIQ-SE administrator session activity for anomalous access patterns to credential configuration pages
• Implement network traffic analysis to detect bulk extraction of configuration data from the management interface
• Deploy SIEM correlation rules to identify successful authentications to downstream systems using XIQ-SE stored credentials by unexpected sources
• Enable comprehensive audit logging for all administrative actions within XIQ-SE

Monitoring Recommendations

• Configure alerts for multiple rapid requests to credential-containing configuration endpoints
• Implement behavioral analytics for administrator accounts to detect deviation from normal access patterns
• Monitor for unauthorized credential usage across the network infrastructure managed by XIQ-SE
• Review access logs for evidence of HTTP response inspection tooling or proxy usage against the management interface

How to Mitigate CVE-2026-0689

Immediate Actions Required

• Upgrade ExtremeCloud IQ – Site Engine to version 26.2.10 or later immediately
• Rotate all credentials stored within XIQ-SE after upgrading to prevent use of potentially compromised secrets
• Audit administrator accounts for unusual activity or access patterns prior to remediation
• Review downstream systems for signs of unauthorized access using XIQ-SE stored credentials

Patch Information

Extreme Networks has released a security update addressing this vulnerability. Organizations running affected versions should upgrade to XIQ-SE version 26.2.10 or later. Detailed patch information and upgrade instructions are available in the Extreme Networks Security Advisory.

After applying the patch, organizations should perform a full credential rotation for all secrets stored within XIQ-SE to ensure any previously exposed credentials are invalidated.

Workarounds

• Restrict network access to the XIQ-SE management interface to dedicated management VLANs or jump hosts
• Implement additional network-level monitoring for traffic to and from the XIQ-SE management interface
• Limit the number of NAC administrator accounts and enforce strict need-to-know access controls
• Consider implementing additional layers of authentication or network segmentation to reduce exposure pending upgrade
• Review and minimize the credentials stored within XIQ-SE where alternative credential management approaches are feasible