EUVD-2026-30185Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Lifecycle Timeline
2DescriptionGitHub Advisory
OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.7, a logic flaw in the OPNsense lockout_handler allows an unauthenticated attacker to continuously reset the authentication failure counter for their IP address. By interjecting a crafted username containing a success keyword ("Accepted" or "Successful login") between normal brute-force attempts, an attacker can prevent the failure counter from ever reaching the lockout threshold. This vulnerability is fixed in 26.1.7.
AnalysisAI
Brute-force lockout bypass in OPNsense prior to 26.1.7 allows unauthenticated remote attackers to indefinitely circumvent the authentication failure counter, enabling unlimited credential guessing against any network-accessible login endpoint. The flaw resides in the lockout_handler logic, which interprets attacker-controlled username strings containing the keywords 'Accepted' or 'Successful login' as success signals and resets the IP-based failure counter. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | No special configuration is required beyond network reachability of the OPNsense authentication endpoint (web management UI or SSH). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | Despite a moderate CVSS base score of 5.3, the real-world risk to internet-facing OPNsense deployments is meaningfully elevated by several converging signals. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker identifies an internet-facing OPNsense firewall with its management web interface or SSH exposed. They initiate an automated credential-stuffing or dictionary attack, but between each failed login attempt, they submit a login request using a crafted username string such as 'Accepted' or 'Successful login', which causes the lockout_handler to reset the failure counter for the attacker's IP. … |
| Remediation | Upgrade OPNsense core to version 26.1.7 or later, which contains the vendor-released fix as confirmed by the GitHub Security Advisory GHSA-h3vx-4q27-rc42. … Detailed patch versions, workarounds, and compensating controls in full report. |
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