Security readout for executives and security teams
Plain-English summary
A Plesk for Linux flaw can let a customer or reseller who has shell access, or can enable it, gain root control of the hosting server. Root compromise could expose or alter every hosted account, website, and service on that server.
Executive priority
Treat as an urgent remediation for affected multi-tenant Plesk servers. Prioritize internet-facing hosting systems where untrusted customers or resellers have shell capabilities. Root compromise creates server-wide confidentiality, integrity, and availability risk, although the supplied sources do not report active exploitation.
Technical view
CVE-2026-67394 is a CWE-78 OS command injection vulnerability affecting specified Plesk for Linux releases from 18.0.34. It enables privilege escalation to root when an eligible customer or reseller has shell access or permission to change their shell access. The CVSS 4.0 score is 9.0.
Likely exposure
Exposure is concentrated on Linux hosting servers running affected Plesk releases, especially multi-tenant systems where customers or resellers have shell access or can enable it. Systems below 18.0.34 or outside the stated affected ranges are not established as vulnerable by this bundle.
Exploitation context
The source bundle provides no evidence of active exploitation, public exploit availability, or confirmed attacks. The CVE is not listed as KEV in the supplied data. Exploitation requires an authenticated customer or reseller meeting the stated shell-access prerequisite.
Researcher notes
The CVSS 4.0 vector reports AV:N, AC:L, AT:P, PR:L, UI:N and high impacts across vulnerable and subsequent systems. The vendor description nevertheless identifies shell access, or permission to change it, as a prerequisite. The supplied version wording is somewhat ambiguous, so confirm exact affected ranges in current Plesk guidance.
Mitigation direction
- Update affected 18.0.79 releases to 18.0.79.9 or later, following Plesk guidance.
- Update affected 18.0.80 releases to 18.0.80.5 or later, following Plesk guidance.
- Temporarily restrict customer and reseller shell access until affected servers are updated.
- Review whether customers or resellers can change their own shell-access settings.
Validation and detection
- Inventory Plesk for Linux servers and record each exact installed version.
- Identify customers and resellers with shell access or permission to enable it.
- Confirm affected branches meet the vendor-stated fixed version thresholds.
- Review relevant administrative and root-activity logs for unexplained privilege changes.
- Consult the Plesk advisory for clarified ranges, updates, and any newly published indicators.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-67394 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H——hackeroneVulnerability scoring details
Base CVSS 4.0 score
9CriticalVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.