CVE-2026-1498: WatchGuard Fireware OS LDAP Injection Flaw

CVE-2026-1498 Overview

An LDAP Injection vulnerability (CWE-90) has been identified in WatchGuard Fireware OS that may allow a remote unauthenticated attacker to retrieve sensitive information from a connected LDAP authentication server through an exposed authentication or management web interface. This vulnerability may also enable a remote attacker to authenticate as an LDAP user with a partial identifier if they additionally possess that user's valid passphrase.

Critical Impact

Remote unauthenticated attackers can exploit this LDAP injection flaw to exfiltrate sensitive data from connected LDAP servers and potentially bypass authentication controls on affected WatchGuard firewall appliances.

Affected Products

• WatchGuard Fireware OS versions 12.0 through 12.11.6
• WatchGuard Fireware OS versions 12.5 through 12.5.15
• WatchGuard Fireware OS versions 2025.1 through 2026.0

Discovery Timeline

• 2026-01-30 - CVE CVE-2026-1498 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2026-1498

Vulnerability Analysis

This LDAP Injection vulnerability exists within WatchGuard Fireware OS's handling of user-supplied input when constructing LDAP queries through the authentication or management web interfaces. The vulnerability allows attackers to manipulate LDAP queries by injecting malicious characters and operators that modify the intended query logic.

When user input is not properly sanitized before being incorporated into LDAP search filters, attackers can inject special LDAP metacharacters such as parentheses (), asterisks *, or logical operators to alter query behavior. This can result in unauthorized data retrieval from the connected LDAP directory server, potentially exposing user credentials, group memberships, organizational information, and other sensitive directory attributes.

The secondary authentication bypass aspect of this vulnerability is particularly concerning. An attacker who possesses a valid user's passphrase may be able to authenticate using only a partial user identifier by manipulating the LDAP query to match multiple or alternative user records.

Root Cause

The root cause of this vulnerability is improper input validation and sanitization of user-supplied data before it is used to construct LDAP queries. The affected web interfaces fail to adequately escape or filter LDAP metacharacters and special syntax, allowing attackers to break out of the intended query structure and inject their own LDAP filter expressions.

Attack Vector

The attack is conducted remotely over the network without requiring authentication. An attacker targets the exposed authentication or management web interface of the WatchGuard Fireware OS appliance. By crafting malicious input containing LDAP injection payloads, the attacker can manipulate backend LDAP queries to extract sensitive information from the connected LDAP authentication server.

The attack surface includes any externally accessible authentication portals or management interfaces that process LDAP queries. Network exposure of these interfaces significantly increases the risk, particularly when management interfaces are accessible from untrusted networks.

Detection Methods for CVE-2026-1498

Indicators of Compromise

• Unusual LDAP query patterns in authentication logs containing special characters such as *, )(, or encoded filter operators
• Failed authentication attempts with abnormally formatted usernames or containing LDAP metacharacters
• Unexpectedly successful authentication events for user accounts with incomplete or partial identifiers
• Increased LDAP traffic or query volume from WatchGuard appliances to connected directory servers

Detection Strategies

• Monitor authentication logs on WatchGuard appliances for entries containing LDAP injection patterns such as )(, *)(, or |( sequences
• Implement network-based detection rules to identify HTTP requests to management interfaces containing URL-encoded LDAP metacharacters
• Configure LDAP server logging to capture and alert on queries with unusual filter structures or excessive attribute enumeration
• Deploy Web Application Firewall (WAF) rules to detect and block common LDAP injection payloads in web traffic

Monitoring Recommendations

• Enable verbose logging on WatchGuard Fireware OS authentication services and forward logs to a SIEM for centralized analysis
• Monitor LDAP server performance metrics for anomalous query patterns or increased load that may indicate exploitation attempts
• Implement alerting for authentication events originating from unexpected geographic locations or IP addresses
• Regularly review access logs for the management web interface to identify unauthorized access attempts

How to Mitigate CVE-2026-1498

Immediate Actions Required

• Restrict access to WatchGuard management interfaces to trusted internal networks only using firewall rules
• Implement network segmentation to limit exposure of authentication portals to untrusted networks
• Review and audit LDAP server access controls to minimize the data accessible through compromised queries
• Enable multi-factor authentication where supported to mitigate the authentication bypass aspect of the vulnerability

Patch Information

WatchGuard has released a security advisory addressing this vulnerability. Administrators should consult the WatchGuard Security Advisory for detailed patching instructions and updated firmware versions that remediate this issue. Upgrade Fireware OS to a version that addresses CVE-2026-1498 as soon as patches become available.

Workarounds

• Disable external access to management and authentication web interfaces until patches can be applied
• Place WatchGuard appliances behind an additional reverse proxy or WAF configured to filter LDAP injection patterns
• Implement IP allowlisting for management interface access to restrict connections to known administrator addresses
• Consider temporarily disabling LDAP authentication in favor of local authentication if operationally feasible

# Restrict management interface access to specific trusted networks
# Example WatchGuard policy configuration approach
# Consult WatchGuard documentation for exact CLI syntax

# 1. Access the WatchGuard CLI via serial or SSH
# 2. Configure trusted host restrictions for management access
# 3. Apply network policies to limit authentication portal exposure

# Verify current management access settings
show configuration management-access

# Apply IP-based restrictions to management interfaces
# Refer to WatchGuard PSIRT advisory for specific remediation steps