CVE-2026-43634CWE-348

HestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP Header

High · published May 19, 2026

CVSS v4.0
8.7
EPSS
0%
Percentile
28.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.7 · HIGH
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
EPSS
0.00362 · 28.8th percentile
Weakness
CWE-348 · Use of Less Trusted Source
Published
2026-05-19T13:33Z
EPSS history
Timeline
  • 19 MAY 13:33Z
    HestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP Header
    cvelistv5