CVEvulnerability
CVE-2026-43634
8.7 HIGH
Official page ↗
- Status
- Deferred
- Published
- 2026-05-19
- Last modified
- 2026-07-24
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 8.7 HIGH — 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
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Weaknesses
- CWE-348
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.
Related
Weakness · CWE (1)
- CWE-348 Use of Less Trusted Source weakness
References
- https://github.com/hestiacp/hestiacp/commit/f381e294500f671cf12716c638afd0bfde901f88 github.com
- https://github.com/hestiacp/hestiacp/issues/5229 github.com
- https://github.com/hestiacp/hestiacp/pull/5273 github.com
- https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634 mercuryiss.com.au
- https://www.vulncheck.com/advisories/hestiacp-ip-spoofing-via-cf-connecting-ip-header www.vulncheck.com