CVE-2026-63442

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.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.2

Attack Vector ADJACENT_NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/opnsense/core/commit/8bdaad95f405f4587bb83bf35aa652ca493cc2a4
https://github.com/opnsense/core/commit/c930ab586ffe2d2e010e5135657e5e054316ff58
https://github.com/opnsense/core/security/advisories/GHSA-2v2x-m4j7-76pv

Configurations

No configuration.

History

15 Oct 2026, 16:18

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-15 16:18

Updated : 2026-10-16 18:18

NVD link : CVE-2026-63442

Mitre link : CVE-2026-63442

CVE.ORG link : CVE-2026-63442

JSON object : View

Products Affected

No product.

CWE

CWE-117

Improper Output Neutralization for Logs

{"id": "CVE-2026-63442", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-63442", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-15T20:24:38.956809Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.1, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 5.2, "exploitabilityScore": 2.8}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "opnsense", "product": "core", "versions": [{"status": "affected", "version": "< 26.1.11"}]}]}], "published": "2026-10-15T16:18:19.157", "references": [{"url": "https://github.com/opnsense/core/commit/8bdaad95f405f4587bb83bf35aa652ca493cc2a4", "source": "security-advisories@github.com"}, {"url": "https://github.com/opnsense/core/commit/c930ab586ffe2d2e010e5135657e5e054316ff58", "source": "security-advisories@github.com"}, {"url": "https://github.com/opnsense/core/security/advisories/GHSA-2v2x-m4j7-76pv", "source": "security-advisories@github.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-117"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-10-16T18:18:00.230", "sourceIdentifier": "security-advisories@github.com"}