CVE-2026-43633Public exploitNetwork attack vector

Unauthenticated root shell via session parser mismatch

Published May 19, 2026 · Updated May 19, 2026

Session deserialization in Hestia Control Panel 1.9.0 through 1.9.5 allows remote attackers to obtain a root shell via HTTP headers. The web terminal's Node.js server splits raw PHP session text and treats an X-Forwarded-For substring as the authenticated username. The web terminal must be enabled; successful exploitation spawns a root shell with full server read, write, and command access.

CVSS severity9.5
Critical
EPSS probability1.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Session deserialization in Hestia Control Panel 1.9.0 through 1.9.5 allows remote attackers to obtain a root shell via HTTP headers. The web terminal's Node.js server splits raw PHP session text and treats an X-Forwarded-For substring as the authenticated username. The web terminal must be enabled; successful exploitation spawns a root shell with full server read, write, and command access.

The record

CVE
CVE-2026-43633
Published
May 19, 2026
Updated
May 19, 2026
Vendor
Hestia Control Panel
Product
Hestia Control Panel
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 2026CVE publishedPublication date reported by the CVE source.
  2. May 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.9.0 <=1.9.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Hestia Control Panel · Hestia Control Panelversion=1.9.0 <=1.9.4

Published CVSS scores

9.8Hestia Control PanelCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.5VulnCheckCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
10.0VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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