Description
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.
Affected products
opnsense: opnsense
References2
- github.com/opnsense/core/security/advisories/GHSA-h3vx-4q27-rc42 ExploitMitigationVendor Advisory
- gist.github.com/sopex/b9786e72e2a5d9b1bbd81ed8477c351b Exploit
Metrics
- CVSS 3.1
-
6.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 25 · as of 14 November 2026
- CWE
- CWE-307
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