CVE-2026-43633NVD
Vulnerability Summary
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 v4.0 Base Metrics — Score 9.5 (CRITICAL)
Attack VectorNetwork
Attack ComplexityLow
Attack RequirementsPresent
Privileges RequiredNone
User InteractionNone
Confidentiality (Vulnerable System)High
Integrity (Vulnerable System)High
Availability (Vulnerable System)High
Confidentiality (Subsequent System)High
Integrity (Subsequent System)High
Availability (Subsequent System)High
CVSS v3.1 Base Metrics — Score 10.0 (CRITICAL)
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
Affected & Patched Versions
- hestiacp hestiacp >= 1.9.0 and <= 1.9.4
- hestiacp hestiacp 1.9.4
External References
- https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634
- https://github.com/hestiacp/hestiacp/issues/5229
- https://github.com/hestiacp/hestiacp/pull/5244
- https://github.com/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6719b
- https://www.vulncheck.com/advisories/hestiacp-deserialization-rce-via-web-terminal