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.
Published: 2026-05-19
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Tue, 19 May 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 19 May 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Hestiacp
Hestiacp hestiacp
Vendors & Products Hestiacp
Hestiacp hestiacp

Tue, 19 May 2026 14:30:00 +0000

Type Values Removed Values Added
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.
Title HestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP Header
Weaknesses CWE-348
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

cvssV4_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'}


Subscriptions

Hestiacp Hestiacp
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-05-19T16:39:31.444Z

Reserved: 2026-05-01T18:22:45.641Z

Link: CVE-2026-43634

cve-icon Vulnrichment

Updated: 2026-05-19T16:39:27.735Z

cve-icon NVD

Status : Deferred

Published: 2026-05-19T15:16:31.023

Modified: 2026-06-17T10:49:56.077

Link: CVE-2026-43634

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-19T15:30:08Z

Weaknesses