Improper Output Neutralization for Logs in OPNsense - #VU136839
Published: July 3, 2026 / Updated: July 3, 2026
Vulnerability identifier: #VU136839
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green
CVE-ID: N/A
CWE-ID: CWE-117
Exploitation vector: Adjecent network
Exploit availability:
Public exploit is available
Vendor: Deciso
Affected software:
OPNsense
OPNsense
Detailed vulnerability description
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to insufficient neutralization of special characters when writing to logs within login username field. A remote attacker on the local network can bypass brute-force protection and perform a denial of service (DoS) attack.
Remediation
Install updates from vendor's website.