CVE-2026-43634
⚠️ highSummary
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.
CVSS Score
7.5
High
EPSS Score
-
Published Date
2026-05-19
First Seen: 2026-05-20
📊 Relative Risk Intelligence
This CVE is Moderate Risk - more severe than 69.1% of all 321,566 vulnerabilities in our database.
#99,499
Above average severity
Severity Percentile
🎯 CISA SSVC Assessment Updated: May 19, 2026
🔍 Exploitation Status
Poc
Proof-of-concept available
⚙️ Automatable
YES
Can be exploited automatically
💥 Technical Impact
Partial
Limited system impact
🏆 Discovered By
sutol
divinity76 (remediation developer)
SSVC data provided by
CISA
Last Modified
2026-05-19
Source
NVD 🔗
CVSS Vector 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS Vector 4.0
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
CWE IDs (Weakness Types)