CVE-2026-34578: high-severity vulnerability in opnsense core
OPNsense has an LDAP Injection via Unsanitized Username in Authentication
Published
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.2epss 0.5%
exploitation probability
0.5%top 61% of all CVEs
observed exploitation
nono source reports it
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Affected products
opnsense · coreRelated CVEs — opnsense core
In the same product, most dangerous first.
CVE-2026-44193CRITICALOPNsense: RCE via XMLRPC endpoint using `opnsense.restore_config_section` methodEPSS 0.9%CVE-2026-45158CRITICALOPNsense: Command Injection via Attacker-Controlled DHCP ConfigEPSS 0.8%CVE-2026-44194CRITICALOPNsense: RCE on user managmentEPSS 0.8%CVE-2026-53581CRITICALntp: write path traversalEPSS 0.5%CVE-2026-44195MEDIUMOPNsense: Authentication lockout bypassEPSS 0.4%CVE-2026-30868MEDIUMCross-Site Request Forgery (CSRF) in opnsense/coreEPSS 0.2%