CVE-2026-43634

Signals

NVD · CVE-2026-64604 · In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode When updating CR8NVD · CVE-2026-64603 · In the Linux kernel, the following vulnerability has been resolved: platform/x86: intel-hid: Protect ACPI notify handler against recursion Since commit e2ffcda1NVD · CVE-2026-64602 · In the Linux kernel, the following vulnerability has been resolved: iio: adc: spear: Initialize completion before requesting IRQ In the report from Jaeyoung ChuNVD · CVE-2026-64601 · In the Linux kernel, the following vulnerability has been resolved: ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on eachCISA KEV · CVE-2026-63077 · 9.8 · JetBrains TeamCity Deserialization of Untrusted Data Vulnerability · Added 2026-08-05 · Due 2026-08-08CISA KEV · CVE-2026-18556 · 7.4 · N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability · Added 2026-08-04 · Due 2026-08-07NVD · CVE-2026-64604 · In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode When updating CR8NVD · CVE-2026-64603 · In the Linux kernel, the following vulnerability has been resolved: platform/x86: intel-hid: Protect ACPI notify handler against recursion Since commit e2ffcda1NVD · CVE-2026-64602 · In the Linux kernel, the following vulnerability has been resolved: iio: adc: spear: Initialize completion before requesting IRQ In the report from Jaeyoung ChuNVD · CVE-2026-64601 · In the Linux kernel, the following vulnerability has been resolved: ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on eachCISA KEV · CVE-2026-63077 · 9.8 · JetBrains TeamCity Deserialization of Untrusted Data Vulnerability · Added 2026-08-05 · Due 2026-08-08CISA KEV · CVE-2026-18556 · 7.4 · N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability · Added 2026-08-04 · Due 2026-08-07

CVE Database · CVE-2026-43634

CVE-2026-43634

· HIGHDeferred

CVSS v3.1

7.5

CVSS v4.0

8.7

EPSS

0.24%

Published

May 19, 2026

Modified

Jul 24, 2026

Public PoC / Exploit

All weaponized →

No public PoC or exploit code indexed for this CVE.

Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.

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.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Weaknesses (CWE)

CWE-348

References (5)

https://github.com/hestiacp/hestiacp/commit/f381e294500f671cf12716c638afd0bfde901f88

https://github.com/hestiacp/hestiacp/issues/5229

https://github.com/hestiacp/hestiacp/pull/5273

https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634

https://www.vulncheck.com/advisories/hestiacp-ip-spoofing-via-cf-connecting-ip-header

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