---
id: CVE-2026-43633
title: HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal
summary: >-
  HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability
  in the web terminal component caused by a session format mismatch between PHP
  and Node.js that allows unauthenticated remote attackers to achieve root-level
  co…
severity: critical
cvss: 10
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-502
vendor: hestiacp
product: hestiacp
affected:
  - hestiacp >= 1.9.0 <= 1.9.4
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-05-19T13:59:09.185218Z'
exploitAvailable: true
published: '2026-05-19'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T14:03:27.763Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43633'
references:
  - url: >-
      https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634
  - url: 'https://github.com/hestiacp/hestiacp/issues/5229'
  - url: 'https://github.com/hestiacp/hestiacp/pull/5244'
  - url: >-
      https://github.com/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6719b
  - url: >-
      https://www.vulncheck.com/advisories/hestiacp-deserialization-rce-via-web-terminal
tags:
  - cve.org
  - exploit-available
epss: 0.01072
epssPercentile: 0.65119
ingestedAt: '2026-11-08T14:51:22.429Z'
---

## Overview

HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a session format mismatch between PHP and Node.js that allows unauthenticated remote attackers to achieve root-level code execution. Attackers can inject crafted data into HTTP headers that are processed by the PHP session handler but incorrectly deserialized by the Node.js web terminal component as trusted session values, resulting in arbitrary command execution on systems with the web terminal feature enabled.

## Affected

- `hestiacp >= 1.9.0 <= 1.9.4`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.