Critical Injection

CVE-2026-67394 — OS Command Injection in WebPros Plesk

A critical local privilege escalation via OS command injection vulnerability has been discovered in Plesk for Linux, affecting all versions from 18.0.34 before 18.0.79.9 and 18.0.80.5. The vulnerability allows a customer or reseller with shell access (or allowed to change their own shell access) to elevate privileges to the root account on the hosting server.

Published Sep 1, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: hackerone

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

WebPros

Plesk

CVSS base

9.0

Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (WebPros Plesk).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
WebPros	Plesk	≥ 18.0.34 and < 18.0.79.9≥ 18.0.80 and < 18.0.80.5	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Attack requirements

Present

Privileges required

Low

User interaction

None

Scope

Confidentiality (vulnerable system)

High

Integrity (vulnerable system)

High

Availability (vulnerable system)

High

Confidentiality (subsequent)

High

Integrity (subsequent)

High

Availability (subsequent)

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.0	CVSS 4.0	Critical	—	—	support@hackerone.com via NIST National Vulnerability Database
9.0	CVSS 4.0	Critical	—	—	hackerone via CVE Program (cve.org) e CISA ADP

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/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

(score shown at the top: support@hackerone.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-78 · OS Command Injection

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Look for parameters with command/query metacharacters and unexpected child processes of the service.

web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · webpros/plesk
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 9.0
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Undergoing Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 1, 2026 · hackerone

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

1 on the record

support.plesk.com/hc/en-us/articles/42968165026967-CVE-2026-67394-Vulnerability-in-Ples
NIST National Vulnerability Database

Elsewhere on this site

WebPros
every CVE for this vendor

Injection
same class

CWE-78
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-68492 Untrusted Search Path in WebPros Plesk 22d
Critical CVE-2026-68487 Path traversal in Plesk's Backup Manager causes arbitrary file write as root by an… Sep 10, 2026
Critical CVE-2026-68488 TOCTOU Race Condition in WebPros Plesk Sep 10, 2026
High CVE-2026-67397 Path Traversal in WebPros Plesk Sep 3, 2026
Critical CVE-2026-65646 Injection in WebPros Plesk Aug 26, 2026
High CVE-2026-65642 Authorization Bypass Through User-Controlled Key (IDOR) in WebPros Plesk Aug 26, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-67394 is "OS Command Injection in WebPros Plesk", rated Critical. It affects Plesk (WebPros); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.0 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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