{"api_version":"1","generated_at":"2026-10-21T05:06:16+00:00","cve":"CVE-2026-109786","urls":{"html":"https://cve.report/CVE-2026-109786","api":"https://cve.report/api/cve/CVE-2026-109786.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-109786","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-109786"},"summary":{"title":"CVE-2026-109786","description":"In fail2ban 0.10.5 through 1.1.1 before ddd879d, the sshd filter (config/filter.d/sshd.conf) accepts an \"on <token>\" suffix after the host address. Because OpenSSH logs the offered username verbatim, a remote unauthenticated attacker can use a username such as \"x VICTIM-SOURCE-IP-ADDRESS on\" to make fail2ban associate failed login attempts with an arbitrary source IP address and ban it (e.g., to block logins from a legitimate user). 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