CVE-2026-63442 (GCVE-0-2026-63442)

Vulnerability from cvelistv5 – Published: 2026-10-15 15:22 – Updated: 2026-10-16 17:13
VLAI
Title
OPNsense: Log Forgery via Login Username CRLF in WebGUI Authentication → Pf Table IP Blocking
Summary
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.
Severity
8.1 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-15 20:24 UTC
CWE
  • CWE-117 - Improper Output Neutralization for Logs
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7771 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
opnsense core Affected: < 26.1.11
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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