CVE-2026-34578CWE-90

OPNsense has an LDAP Injection via Unsanitized Username in Authentication

High · published April 9, 2026

CVSS v3.1
8.2
EPSS
0%
Percentile
40.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.2 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00476 · 40.1th percentile
Weakness
CWE-90 · Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
Published
2026-04-09T14:34Z
EPSS history
Timeline
  • 09 APR 14:34Z
    OPNsense has an LDAP Injection via Unsanitized Username in Authentication
    cvelistv5