CVSS 4.0
9.5 criticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HCVE-2026-43633
Critical (9.5). EPSS 1.1% chance of exploitation in the next 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.
Severity
CVSS 3.1
10.0 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H- EPSS
- 1.1% chance of exploitation in the next 30 days; higher than 64% of CVEs (scores of 2026-10-31)
- CWE
- CWE-502
- Published
- Modified
- Record from
- the NVD, synced
References
- https://github.com/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6719b
- https://github.com/hestiacp/hestiacp/issues/5229
- https://github.com/hestiacp/hestiacp/pull/5244
- https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634
- https://www.vulncheck.com/advisories/hestiacp-deserialization-rce-via-web-terminal