by Kastro
Paper/Archive/CVE-2026-43633

CVE-2026-43633

hestiacp hestiacp — HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal

EPSS 1%public exploitCVSS 10.0
critical.is priorityof 100
53
CVSS 10.0 (CNA)10.0 / 10 × 3030.0Not in CISA KEV+300.0EPSS percentile 64.9.649 × 2013.0Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
hestiacp1.9.0 – 1.9.4–CNA

Scores by source

VulnCheck (CNA)10.0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
VulnCheck (CNA)9.5CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CISA ADPSSVCExploitation: poc · Automatable: yes · Technical impact: total

References

exploitmercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634refgithub.com/hestiacp/hestiacp/issues/5229refgithub.com/hestiacp/hestiacp/pull/5244patchgithub.com/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6719bwriteupvulncheck.com/advisories/hestiacp-deserialization-rce-via-web-terminal