CVE-2026-34578: CWE-90: Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection') in opnsense core
OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.6, OPNsense's LDAP authentication connector passes the login username directly into an LDAP search filter without calling ldap_escape(). An unauthenticated attacker can inject LDAP filter metacharacters into the username field of the WebGUI login page to enumerate valid LDAP usernames in the configured directory. When the LDAP server configuration includes an Extended Query to restrict login to members of a specific group, the same injection can be used to bypass that group membership restriction and authenticate as any LDAP user whose password is known, regardless of group membership. This vulnerability is fixed in 26.1.6.
AI Analysis
Technical Summary
OPNsense core before version 26.1.6 contains an LDAP injection vulnerability (CWE-90) due to improper neutralization of special elements in LDAP queries. The login username is passed directly into an LDAP search filter without escaping, allowing injection of LDAP filter metacharacters. This enables unauthenticated attackers to enumerate valid LDAP usernames and bypass group membership restrictions in LDAP authentication, potentially authenticating as any LDAP user with a known password. The issue is resolved in OPNsense 26.1.6.
Potential Impact
An attacker can enumerate valid LDAP usernames via injection in the WebGUI login username field. Additionally, when LDAP server configuration uses an Extended Query to restrict logins to specific groups, the injection can bypass these restrictions, allowing authentication as any LDAP user with a known password regardless of group membership. This compromises authentication integrity and user access controls.
Mitigation Recommendations
This vulnerability is fixed in OPNsense version 26.1.6. Users should upgrade to version 26.1.6 or later to remediate this issue. Patch status is not explicitly stated beyond the fix in 26.1.6, so users should consult the official OPNsense release notes or advisories for confirmation and further guidance.
CVE-2026-34578: CWE-90: Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection') in opnsense core
Description
OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.6, OPNsense's LDAP authentication connector passes the login username directly into an LDAP search filter without calling ldap_escape(). An unauthenticated attacker can inject LDAP filter metacharacters into the username field of the WebGUI login page to enumerate valid LDAP usernames in the configured directory. When the LDAP server configuration includes an Extended Query to restrict login to members of a specific group, the same injection can be used to bypass that group membership restriction and authenticate as any LDAP user whose password is known, regardless of group membership. This vulnerability is fixed in 26.1.6.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
OPNsense core before version 26.1.6 contains an LDAP injection vulnerability (CWE-90) due to improper neutralization of special elements in LDAP queries. The login username is passed directly into an LDAP search filter without escaping, allowing injection of LDAP filter metacharacters. This enables unauthenticated attackers to enumerate valid LDAP usernames and bypass group membership restrictions in LDAP authentication, potentially authenticating as any LDAP user with a known password. The issue is resolved in OPNsense 26.1.6.
Potential Impact
An attacker can enumerate valid LDAP usernames via injection in the WebGUI login username field. Additionally, when LDAP server configuration uses an Extended Query to restrict logins to specific groups, the injection can bypass these restrictions, allowing authentication as any LDAP user with a known password regardless of group membership. This compromises authentication integrity and user access controls.
Mitigation Recommendations
This vulnerability is fixed in OPNsense version 26.1.6. Users should upgrade to version 26.1.6 or later to remediate this issue. Patch status is not explicitly stated beyond the fix in 26.1.6, so users should consult the official OPNsense release notes or advisories for confirmation and further guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-30T16:56:30.998Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d7bccb1cc7ad14dad7b126
Added to database: 4/9/2026, 2:50:51 PM
Last enriched: 4/9/2026, 3:05:47 PM
Last updated: 4/10/2026, 7:35:28 AM
Views: 6
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