CVE-2026-43633: critical vulnerability in hestiacp
HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal
Published · Updated
48Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 9.5epss 1.5%
exploitation probability
1.5%top 27% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
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:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Affected products
hestiacp · hestiacppublic PoCs found — 1
cve_referencemercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634unverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
Related CVEs — hestiacp
In the same product, most dangerous first.
CVE-2025-30007HIGHHestiaCP < 1.9.5 Authenticated OS Command Injection via DNS Record ManagementEPSS 3.2%CVE-2026-12196HIGHHestiaCP Admin TakeoverEPSS 0.4%CVE-2026-43634HIGHHestiaCP 1.2.0-1.9.4 IP Spoofing via CF-Connecting-IP HeaderEPSS 0.4%CVE-2025-30008MEDIUMHestiaCP < 1.9.5 Stored XSS via DNS Record Management InterfaceEPSS 0.3%
References
https://github.com/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6719bhttps://github.com/hestiacp/hestiacp/issues/5229https://github.com/hestiacp/hestiacp/pull/5244https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634https://www.vulncheck.com/advisories/hestiacp-deserialization-rce-via-web-terminal