CVE•Published 2026-10-13•Modified 2026-10-16•0 articles on news•4 live references•NVD data
CVE-2026-109786
Vulnerability data via NVD (ingested)
CVSS v3.1
5.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS percentile
23
Exploit Prediction Scoring System · top 77% of all CVEs
Weaknesses (CWE)
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). The default filter mode is affected.
Timeline
Published 2026-10-13
Modified 2026-10-16
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
Shodan · vuln tag0 hosts
vuln:CVE-2026-109786Hosts Shodan has explicitly fingerprinted as vulnerable.
More intel sources (5)
Shodan report
vuln:CVE-2026-109786Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-109786Censys host search filtered to this CVE id.
grep.app
CVE-2026-109786Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-109786GitHub code search for direct mentions.
Google dork
"CVE-2026-109786" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2026-109786 on GitHub.
We haven't classified any articles referencing CVE-2026-109786 yet. The external references above still apply.