{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-43634", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-05-01T18:22:45.641Z", "datePublished": "2026-05-19T13:33:08.825Z", "dateUpdated": "2026-05-19T14:16:09.275Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-05-19T14:16:09.275Z"}, "title": "HestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP Header", "descriptions": [{"lang": "en", "value": "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."}], "tags": ["x_open-source"], "datePublic": "2026-03-09T00:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-348", "description": "Use of Less Trusted Source", "type": "CWE"}]}], "affected": [{"vendor": "hestiacp", "product": "hestiacp", "repo": "https://github.com/hestiacp/hestiacp", "versions": [{"status": "affected", "version": "1.2.0", "lessThanOrEqual": "1.9.4", "versionType": "semver"}, {"status": "unaffected", "version": "f381e294500f671cf12716c638afd0bfde901f88", "versionType": "git"}], "defaultStatus": "affected"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "HIGH", "baseScore": 8.7, "vectorString": "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"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE", "version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.5, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}}], "references": [{"url": "https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634", "tags": ["technical-description", "exploit"]}, {"url": "https://github.com/hestiacp/hestiacp/issues/5229", "tags": ["issue-tracking"]}, {"url": "https://github.com/hestiacp/hestiacp/pull/5273", "tags": ["issue-tracking"]}, {"url": "https://github.com/hestiacp/hestiacp/commit/f381e294500f671cf12716c638afd0bfde901f88", "tags": ["patch"]}, {"url": "https://www.vulncheck.com/advisories/hestiacp-ip-spoofing-via-cf-connecting-ip-header", "tags": ["third-party-advisory"]}], "credits": [{"lang": "en", "value": "sutol", "type": "finder"}, {"lang": "en", "value": "divinity76", "type": "remediation developer"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "vulncheck"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-43634", "lastModified": "2026-05-19T15:16:31.023", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "disclosure@vulncheck.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-05-19T15:16:31.023", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/hestiacp/hestiacp/commit/f381e294500f671cf12716c638afd0bfde901f88"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/hestiacp/hestiacp/issues/5229"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/hestiacp/hestiacp/pull/5273"}, {"source": "disclosure@vulncheck.com", "url": "https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/hestiacp-ip-spoofing-via-cf-connecting-ip-header"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-348"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.2.0,1.9.4]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "code_commit", "value": "f381e294500f671cf12716c638afd0bfde901f88"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "hestiacp", "source": "cna", "vendor": "hestiacp"}, "product": "hestiacp", "vendor": "hestiacp"}], "created": "2026-05-19T15:30:08.162065+00:00", "updated": "2026-05-19T15:30:08.493349+00:00", "vendors": ["hestiacp", "hestiacp$PRODUCT$hestiacp"]}