CVE-2026-34578

OPNsense has an LDAP Injection via Unsanitized Username in Authentication

State
Published
Severity
8.2 High
Published
Apr 9, 2026
Updated
Apr 9, 2026
Reserved
Mar 30, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.18.2 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:NGitHub_M

Weaknesses

  • CWE-90 Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')

Affected Products

ProductVersions
coreopnsense
  • < 26.1.6Affected

References

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