CVE-2026-26721: Keystorage Global Facilities Management Info Disclosure

CVE-2026-26721 Overview

CVE-2026-26721 is an information disclosure vulnerability affecting Key Systems Inc Global Facilities Management Software version 20230721a. The vulnerability allows a remote attacker to obtain sensitive information by exploiting the sid query parameter. This flaw stems from the use of sensitive GET parameters in URL query strings, which can result in unauthorized access to confidential data.

Critical Impact

Remote attackers can leverage this vulnerability to extract sensitive information from vulnerable installations without authentication, potentially exposing confidential facility management data, user credentials, or session identifiers.

Affected Products

• Keystorage Global Facilities Management Software version 20230721a

Discovery Timeline

• 2026-02-20 - CVE-2026-26721 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2026-26721

Vulnerability Analysis

This vulnerability is classified under CWE-598 (Use of GET Request Method With Sensitive Query Strings). The flaw occurs when the application transmits sensitive information via URL query parameters, specifically through the sid parameter. This design weakness exposes sensitive data in multiple locations including browser history, server logs, proxy logs, and referrer headers.

When sensitive information such as session identifiers or authentication tokens are passed through GET parameters, they become susceptible to interception and logging by intermediate systems. The network-based attack vector means an attacker can exploit this vulnerability remotely without requiring any privileges, though user interaction is required for successful exploitation.

Root Cause

The root cause of CVE-2026-26721 lies in improper handling of sensitive data transmission within the Global Facilities Management Software. The application utilizes GET request methods with sensitive query strings instead of more secure alternatives such as POST requests with encrypted payloads or proper session management techniques. The sid parameter, likely representing a session identifier or sensitive data token, is exposed in URL query strings where it can be captured through various means including browser history, referrer headers, and server access logs.

Attack Vector

The vulnerability can be exploited through a network-based attack where an attacker targets the sid query parameter to extract sensitive information. An attacker could craft malicious links or leverage man-in-the-middle positions to capture URLs containing the sensitive parameter. The attack requires user interaction, such as clicking on a crafted link or visiting a page that leaks the referrer information.

Since the sid parameter is transmitted via GET requests, the sensitive data may be exposed through:

• Browser history and bookmarks
• Web server access logs
• Proxy server logs
• HTTP Referrer headers when navigating to external links
• Shoulder surfing or screen captures showing the URL bar

Detection Methods for CVE-2026-26721

Indicators of Compromise

• Unusual patterns of requests targeting URLs containing the sid query parameter
• Evidence of URL harvesting or parameter tampering in web server access logs
• Unexpected data access patterns indicating session hijacking or credential theft
• Referrer header leakage to external domains containing sensitive sid values

Detection Strategies

• Monitor web server logs for suspicious patterns of requests with sid parameters from unfamiliar IP addresses
• Implement web application firewall (WAF) rules to detect and alert on potential parameter enumeration attacks
• Review proxy and load balancer logs for unusual query string patterns
• Analyze network traffic for GET requests containing sensitive identifiers being transmitted to third parties

Monitoring Recommendations

• Enable comprehensive logging for all HTTP requests containing the sid parameter
• Configure alerting for high volumes of requests with varying sid values from single IP addresses
• Monitor for referrer leakage by tracking outbound links from sensitive application pages
• Implement session anomaly detection to identify potential session hijacking attempts

How to Mitigate CVE-2026-26721

Immediate Actions Required

• Review all instances where the sid parameter is used and assess the sensitivity of data being transmitted
• Implement POST method requests for all sensitive data transmissions as an interim measure
• Restrict access to the vulnerable application until a patch is available
• Review server logs for evidence of exploitation and rotate any potentially compromised session identifiers

Patch Information

No official vendor patch information is currently available for CVE-2026-26721. Organizations should monitor the vendor's security advisories and the GitHub CVE-2026-26721 Disclosures for updates regarding official patches or remediation guidance.

Workarounds

• Migrate sensitive parameter transmission from GET to POST requests where possible
• Implement additional server-side validation and session management controls
• Deploy a Web Application Firewall (WAF) to monitor and filter suspicious requests
• Configure the application to use HTTP-only and Secure flags for session cookies
• Add referrer policy headers to prevent leakage of sensitive URLs to third parties

# Web server configuration to add Referrer-Policy header (Apache example)
# Add to .htaccess or server configuration
Header always set Referrer-Policy "strict-origin-when-cross-origin"

# Nginx configuration example
add_header Referrer-Policy "strict-origin-when-cross-origin" always;