CVE-2026-43633

Description

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.

Predictions

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No vendor mitigations ingested yet for this CVE. The mitigation-content worker queues fetches as references arrive — check back in a few minutes, or see the references list below.

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

CWEs

CWE-502