Vulnerability 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
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Opnsense | Opnsense | < 26.1.6 |
Related Weaknesses (CWE)
References
- https://github.com/opnsense/core/commit/016f66cb4620cd48183fa97843f343bb71813c6ePatch
- https://github.com/opnsense/core/security/advisories/GHSA-jpm7-f59c-mp54ExploitMitigationVendor Advisory
- https://github.com/opnsense/core/security/advisories/GHSA-jpm7-f59c-mp54ExploitMitigationVendor Advisory
FAQ
What is CVE-2026-34578?
CVE-2026-34578 is a vulnerability with a CVSS score of 8.2 (HIGH). 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_...
How severe is CVE-2026-34578?
CVE-2026-34578 has been rated HIGH with a CVSS base score of 8.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-34578?
Check the references section above for vendor advisories and patch information. Affected products include: Opnsense Opnsense.