CVE-2026-34578
8.2 · HIGHOverview
CVE-2026-34578 is a high-severity vulnerability affecting opnsense opnsense. It was published on April 9, 2026 and has a CVSS 3.1 base score of 8.2 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.2, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from opnsense. Update opnsense to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| opnsense | opnsense | >= 0, < 26.1.6 | Affected |
Frequently Asked Questions
What is CVE-2026-34578?
CVE-2026-34578 is a high-severity vulnerability affecting opnsense opnsense. It was published on April 9, 2026 and has a CVSS 3.1 base score of 8.2 (HIGH).
How severe is CVE-2026-34578?
This vulnerability has a CVSS 3.1 base score of 8.2, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-34578?
Check the references section for vendor advisories and patches from opnsense. Update opnsense to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-34578?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-34578 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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