CVE-2026-43633 json
HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal
published 2026-05-19 5 mo ago modified 2026-11-08 20 h ago also EUVD-2026-30933
- cvss
- 10.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 65%
- public exploits
- 0
- none known
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.
Patch / fix
- hestiacp control_panel 1.9.5
- github.com/hestiacp/hestiacp@854d71b commit
- github.com/hestiacp/hestiacp#5244 pull request
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- total
- Assessed
- 5 mo ago
Exploit prediction
1.07% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- mercuryiss.com.au https://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.5 | 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 |
| CNA | 3.1 | 10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| CNA | 4.0 | 9.5 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- hestiacp hestiacp
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
github.com
/hestiacp/hestiacp/pull/5244
issue-tracking, patch
-
github.com
/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6719b
patch
-
mercuryiss.com.au
/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634
technical-description, exploit
-
github.com
/hestiacp/hestiacp/issues/5229
issue-tracking
-
vulncheck.com
/advisories/hestiacp-deserialization-rce-via-web-terminal
third-party-advisory
Sources
- CVE List CVE-2026-43633
- NVD CVE-2026-43633
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.