CVE-2026-63442
HighCVSS 8.1Exploitation Probability (EPSS)
Low risk20th percentile - higher than 20% of all known CVEs
Summary
OPNsense, a FreeBSD-based firewall and routing platform, prior to 26.1.11 allows carriage-return and line-feed characters in the WebGUI login username field. An attacker with network access to the login page can forge authentication events for another IP, adding it to the sshlockout PF table, or reset their own brute-force counter.
Risk Assessment
Administrative, DNS, gateway, or monitoring addresses can be blocked, and password-guessing lockout can be bypassed without authentication.
Recommendation
Update OPNsense to version 26.1.11 or later.
Other vulnerabilities in OPNsense
See all- CVE-2026-57155Critical
In OPNsense prior to 26.1.11, the Firewall Alias GeoIP importer uses an unvalidated CSV country_code value to construct output filenames, allowing path traversal. A user with Firewall Alias Edit privilege can supply a crafted archive and write attacker-controlled content as root, then leverage cron to execute commands as root.
- CVE-2026-53581Critical
OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.9 of opnsense/core and version 26.4_20 of BE/opnsense/core, a path traversal vulnerability in the NTP configuration module allows an attacker to overwrite arbitrary files on the system as the root user. By manipulating the GPS or PPS serial port parameter, an attacker with access to the NTP configuration can escape the intended directory and write user-controlled data to any file.
- CVE-2026-45158Critical
OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.8, unsanitized user input was passed to the DHCP configuration, allowing remote code execution as root on the underlying operating system.
- CVE-2026-44193Critical
OPNsense is a FreeBSD based firewall and routing platform. In versions prior to 26.1.7, the XMLRPC method opnsense.restore_config_section fails to sanitize user supplied input, leading to Remote Code Execution.
- CVE-2023-39004Critical
Insecure permissions in the configuration directory (/conf/) of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allow attackers to access sensitive information (e.g., hashed root password) which could lead to privilege escalation.
- CVE-2026-119560Medium
OPNsense core through 26.7.8 contains a configuration injection vulnerability that allows authenticated users to append ntpd.conf directives by embedding newlines in the fudge and refid fields. Attackers holding the page-services-ntp-gps or PPS privilege can submit CR/LF characters via services_ntpd_gps.php or services_ntpd_pps.php to inject directives loaded by ntpd running as root.
- CVE-2026-119425Medium
OPNsense core 26.1.6 through 26.7.7 contains an authentication bypass vulnerability in the captive portal roaming feature that lets unauthenticated attackers hijack authorized client sessions by spoofing unauthenticated MAC-to-IP observations. Attackers on the same Layer-2 segment can send forged gratuitous ARP replies binding their IP to a victim's MAC, gaining portal access with traffic attributed to the victim.
- CVE-2026-119424Medium
OPNsense core before 26.7.8 contains a configuration line injection vulnerability that allows authenticated users with wireless-edit privilege to inject directives by embedding CR/LF characters in WPA fields. Attackers can place newlines in wpa.identity, wpa.passphrase, or RADIUS shared secrets to append arbitrary wpa_supplicant or hostapd directives loaded by root-run daemons.
- CVE-2026-119423Medium
OPNsense core before 26.7.8 contains a log injection vulnerability that allows unauthenticated attackers to plant victim IP addresses in the lockout_handler by submitting crafted WebGUI login usernames. Attackers can submit usernames like 'Invalid user <victim-ip>' repeatedly to add the victim to the sshlockout table, blocking SSH and WebGUI access and killing its pf states.
- CVE-2026-119409High
OPNsense before 26.7.8 contains a command injection vulnerability that allows authenticated users with the System: Firmware privilege to execute commands as root by storing a malicious firmware mirror URL. Attackers can submit shell metacharacters through POST /api/core/firmware/set that opnsense-update evaluates with eval, and can also disable package signature verification through sed injection.
Original NVD description (English source)
OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, the unauthenticated WebGUI login usernamefld accepts carriage-return and line-feed characters that survive LOG_AUTH processing through syslog-ng-lockout.conf into the syslog-ng program destination feeding lockout_handler. The consumer's readline() processing treats an injected fragment as a separate authentication event and selects the first syntactically valid IP address from the forged line. An attacker with network access to the login page can forge failure events for another IP, causing that IP to be added to the sshlockout PF table and its active states to be killed, or forge accepted events that reset an attacker's own brute-force counter. This can block administrative, DNS, gateway, or monitoring addresses and can bypass password-guessing lockout without authentication. This issue is fixed in version 26.1.11.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

