Unsafe Deserialization in HestiaCP (CVE-2026-43633)
Summary
Vulnerability in HestiaCP (CVE-2026-43633). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-43633 has been found in HestiaCP.
Successful exploitation can lead to full system takeover. CVSS score: 10.0/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "HestiaCP CVE-2026-43633" on the vendor's site.
CVE-2026-43633 (HestiaCP) — CWE-502 / CVSS v3 10.0
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Unsafe deserialization (CWE-502) exists in HestiaCP.
Check the vendor advisory for the affected versions of HestiaCP.
Severity: Critical (CVSS 10.0/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'HestiaCP' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'HestiaCP' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
HestiaCPを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory vulncheck.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- report github.com
- report github.com
- report mercuryiss.com.au
- web github.com