{"id":"CVE-2026-43634","aliases":["EUVD-2026-30935","GHSA-72fg-f46j-5gvp"],"status":"published","title":"HestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP Header","description":"HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00241,"percentile":0.15324,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-348"],"published":"2026-05-19T13:33:08Z","modified":"2026-11-09T02:47:20Z","products":[{"vendor":"hestiacp","product":"hestiacp"}],"references":[{"url":"https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634","tags":["technical-description","exploit","evidence"]},{"url":"https://github.com/hestiacp/hestiacp/issues/5229","tags":["issue-tracking","report"]},{"url":"https://github.com/hestiacp/hestiacp/pull/5273","tags":["issue-tracking","patch","fix"]},{"url":"https://github.com/hestiacp/hestiacp/commit/f381e294500f671cf12716c638afd0bfde901f88","tags":["patch","fix"]},{"url":"https://www.vulncheck.com/advisories/hestiacp-ip-spoofing-via-cf-connecting-ip-header","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43634","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-72fg-f46j-5gvp"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43634.json","tags":["advisory"]},{"url":"https://github.com/hestiacp/hestiacp","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-43634","title":"HestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP Header","description":"HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.","status":"published","published":"2026-05-19T13:33:08.825Z","modified":"2026-11-08T14:03:28.605Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-348"],"updated_at":"2026-11-08T15:43:33.322657Z"}],"euvd":[{"id":"EUVD-2026-30935","description":"HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.","status":"published","published":"2026-05-19T13:33:08Z","modified":"2026-11-08T14:03:28Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-08T15:13:08.77824Z"}],"ghsa":[{"id":"GHSA-72fg-f46j-5gvp","title":"HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows...","description":"HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.","status":"published","published":"2026-05-19T15:31:35Z","modified":"2026-05-19T15:31:41Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-348"],"updated_at":"2026-11-02T15:08:12.004262Z"}],"nvd":[{"id":"CVE-2026-43634","description":"HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.","status":"published","published":"2026-05-19T15:16:31.023Z","modified":"2026-07-24T12:10:00.21Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-348"],"updated_at":"2026-11-02T14:12:19.752984Z"}],"osv":[{"id":"CVE-2026-43634","title":"HestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP Header","description":"HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.","status":"published","published":"2026-05-19T13:33:08.825Z","modified":"2026-11-09T02:47:20.624464349Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-348"],"updated_at":"2026-11-09T03:16:17.543303Z"}]}}