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CVE-2026-34578

⚠️ high
🔍 Scan for this CVE
Summary

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,

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.

CVSS Score
8.2
High
EPSS Score
0.3
Exploit Probability
Published Date
2026-04-09
First Seen: 2026-04-10
📊 Relative Risk Intelligence

This CVE is High Risk - more severe than 79.6% of all 328,009 vulnerabilities in our database.

#66,785
Top 25% most severe
Severity Percentile
🎯 CISA SSVC Assessment Updated: Apr 9, 2026
🔍 Exploitation Status
Poc
Proof-of-concept available
⚙️ Automatable
YES
Can be exploited automatically
💥 Technical Impact
Partial
Limited system impact
SSVC data provided by CISA
Last Modified 2026-04-14
Source NVD 🔗
CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
CWE IDs (Weakness Types)
CWE-90

📦 Affected Products 1

Vendor Product Status Affected Versions
opnsense opnsense Affected
< 26.1.6

🔗 References 2

https://github.com/opnsense/core/commit/016f66cb4620...
Patch
https://github.com/opnsense/core/security/advisories...
Exploit Mitigation Vendor Advisory

🔗 Related CVEs 6

CVE ID Severity CVSS EPSS Summary Published
CVE-2026-44193 ⛔ critical 9.1 0.3 OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.7, the XMLRPC method opnsense.restore_config_se... 2026-05-13
CVE-2026-44194 ⛔ critical 9.1 0.1 OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.8, an authenticated Remote Code Execution (RCE)... 2026-05-13
CVE-2026-44195 🔶 medium 5.3 0.1 OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.7, a logic flaw in the OPNsense lockout_handler... 2026-05-13
CVE-2026-45158 ⛔ critical 9.1 0.2 OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.8, unsanitized user input is passed to the DHCP... 2026-05-13
CVE-2026-30868 🔶 medium 6.3 0.0 OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.4, multiple OPNsense MVC API endpoints perform ... 2026-03-11
CVE-2019-25368 🔶 medium 5.4 0.0 OPNsense 19.1 contains multiple cross-site scripting vulnerabilities in the diag_backup.php endpoint that allow attacker... 2026-02-15
These CVEs affect the same products