CVE-2026-22644: Authentication Bypass Vulnerability

CVE-2026-22644 Overview

CVE-2026-22644 is an information disclosure vulnerability where authentication tokens are passed in URL query parameters instead of secure headers or request bodies. This insecure practice exposes sensitive authentication credentials through multiple vectors including server logs, proxy logs, browser history, and HTTP Referer headers, potentially allowing attackers to hijack user sessions and gain unauthorized access to protected resources.

Critical Impact

Authentication tokens exposed in URLs can be captured by intermediary systems, enabling session hijacking and unauthorized access to user accounts and sensitive data.

Affected Products

• SICK AG products (refer to SICK CSAF White Paper for specific affected products)

Discovery Timeline

• 2026-01-15 - CVE CVE-2026-22644 published to NVD
• 2026-01-16 - Last updated in NVD database

Technical Details for CVE-2026-22644

Vulnerability Analysis

This vulnerability is classified under CWE-598 (Use of GET Request Method With Sensitive Query Strings). The core issue stems from transmitting authentication tokens as URL query parameters rather than through secure mechanisms such as HTTP headers or POST request bodies.

When authentication tokens are included in URLs, they become visible and logged in numerous locations throughout the request chain. Web servers typically log complete request URIs including query strings, meaning authentication tokens are written to access logs. Proxy servers and load balancers in the network path similarly capture and log these URLs. Additionally, if a user navigates from an authenticated page to an external site, the full URL including the token may be transmitted in the HTTP Referer header to the external site.

The network-based attack vector means that any entity with access to network traffic, server logs, or proxy infrastructure could potentially harvest authentication tokens. This vulnerability requires no privileges to exploit once an attacker gains access to any of these log sources.

Root Cause

The root cause is an insecure design decision to transmit authentication tokens via URL query parameters rather than using secure transmission methods. Authentication credentials should be passed through HTTP headers (such as the Authorization header) or within encrypted POST request bodies to prevent inadvertent exposure through logging and referrer leakage mechanisms.

Attack Vector

An attacker can exploit this vulnerability through several methods:

1. Log Access: An attacker with access to web server logs, proxy logs, or CDN logs can extract authentication tokens from recorded request URLs
2. Referer Header Leakage: When users click external links from authenticated pages, the Referer header may expose the full URL including the token to third-party sites
3. Browser History: Authentication tokens remain in browser history and URL bars, accessible to anyone with physical or remote access to the user's device
4. Network Interception: Even with HTTPS, the full URL may be visible to certain network components before encryption

The vulnerability exploits the fundamental design of how URLs and query parameters are handled across the web infrastructure, making token exposure nearly inevitable when this authentication pattern is used.

Detection Methods for CVE-2026-22644

Indicators of Compromise

• Unexpected session activity or logins from unfamiliar IP addresses or geographic locations
• Authentication tokens appearing in web server access logs or proxy logs
• Reports of account compromises without corresponding credential theft incidents
• Unusual referrer traffic patterns showing authenticated URLs reaching external domains

Detection Strategies

• Audit web server and proxy log configurations to identify if authentication tokens are being captured in URL parameters
• Implement security monitoring to detect session tokens appearing in log files or being transmitted via Referer headers
• Review application traffic for authentication requests using GET method with credentials in query strings
• Deploy web application firewalls (WAF) with rules to alert on sensitive data patterns in URL parameters

Monitoring Recommendations

• Enable comprehensive logging and alerting for any authentication-related URL patterns containing token parameters
• Monitor for multiple concurrent sessions from the same authentication token across different IP addresses
• Implement session anomaly detection to identify potential token theft and replay attacks
• Review Referer header logs to detect potential token leakage to external domains

How to Mitigate CVE-2026-22644

Immediate Actions Required

• Review application authentication flows and identify all instances where tokens are passed via URL query parameters
• Transition authentication token transmission to HTTP headers (preferably the Authorization header) or POST request bodies
• Implement log scrubbing or redaction for any URLs that may still contain sensitive parameters during transition
• Rotate all potentially exposed authentication tokens and invalidate existing sessions

Patch Information

Consult the SICK CSAF Security Advisory for specific patch information and updated firmware versions. Additionally, review the SICK Cybersecurity Guidelines for recommended security configurations. For general ICS security best practices, refer to CISA ICS Recommended Practices.

Workarounds

• Configure web servers and proxies to exclude or redact query parameters from access logs
• Implement Content Security Policy headers to restrict referrer information (Referrer-Policy: no-referrer)
• Deploy reverse proxy or WAF rules to strip sensitive query parameters before logging
• Enable short-lived token expiration to limit the window of exposure for any leaked tokens
• Implement IP binding for sessions where feasible to reduce token replay attack effectiveness

# Example Apache configuration to sanitize logs
# Add to httpd.conf or virtual host configuration
# Redact token parameters from access logs
SetEnvIf Request_URI "token=" no-log-token
CustomLog logs/access_log combined env=!no-log-token

# Example Nginx configuration
# Add Referrer-Policy header to prevent token leakage
add_header Referrer-Policy "no-referrer" always;