HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal
Summary
| CVE | CVE-2026-43633 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-19 14:16:43 UTC |
| Updated | 2026-05-19 14:43:04 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 9.5 CRITICAL from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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
EPSS: 0.002030000 probability, percentile 0.420680000 (date 2026-05-26)
Problem Types: CWE-502 | CWE-502 CWE-502 Deserialization of Untrusted Data
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.5 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/C... |
| 4.0 | CNA | CVSS | 9.5 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| 3.1 | [email protected] | Primary | 10 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 10 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
HighSub Integrity
HighSub Availability
HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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 v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/hestiacp/hestiacp/pull/5244 | [email protected] | github.com | |
| github.com/hestiacp/hestiacp/issues/5229 | [email protected] | github.com | |
| github.com/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6... | [email protected] | github.com | |
| www.vulncheck.com/advisories/hestiacp-deserialization-rce-via-web-terminal | [email protected] | www.vulncheck.com | |
| mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2... | [email protected] | mercuryiss.com.au | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: sutol (en)
CNA: divinity76 (en)
There are currently no legacy QID mappings associated with this CVE.