Critical 10.0Published May 19, 2026

CVE-2026-43633HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal

Updated under an hour ago (Oct 27, 2026, 4:30 AM ET)

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Exploited in the last 30 days

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.

CVSS: 10.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-502
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Jul 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

hestiacp hestiacp hestiacp:hestiacp (from the name)	from 1.9.0 through 1.9.4; 854d71b3c1737b0a0d0cc55c926008ffe1f6719b not affected	CNA record

References

References

https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634	technical-description, exploit
https://github.com/hestiacp/hestiacp/issues/5229	issue-tracking
https://github.com/hestiacp/hestiacp/pull/5244	issue-tracking
https://github.com/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6719b	patch
https://www.vulncheck.com/advisories/hestiacp-deserialization-rce-via-web-terminal	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.