CVE-2026-43633CWE-502

HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal

Critical · published May 19, 2026

CVSS v4.0
9.5
EPSS
1%
Percentile
73.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
9.5 · CRITICAL
Vector
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
EPSS
0.01487 · 73.9th percentile
Weakness
CWE-502 · Deserialization of Untrusted Data
Published
2026-05-19T13:29Z
EPSS history
Timeline
  • 19 MAY 13:29Z
    HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal
    cvelistv5