CVE-2026-34578

8.2 HIGH
Published: April 09, 2026 Modified: April 14, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/opnsense/core/security/advisories/GHSA-jpm7-f59c-mp54
Source: security-advisories@github.com
Exploit Mitigation Vendor Advisory
https://github.com/opnsense/core/security/advisories/GHSA-jpm7-f59c-mp54
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Mitigation Vendor Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
8.2 / 10.0
EPSS (Exploit Probability)
0.2%
42th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

opnsense