CVE-2026-86121Network attack vector

Unauthenticated command execution via allow-all local mode

Published Sep 5, 2026 · Updated Sep 8, 2026

Missing authentication in Cua Computer Server before 0.3.42 allows remote attackers to execute arbitrary commands through its HTTP API. When CONTAINER_NAME is unset, the /cmd handler skips credential checks and dispatches attacker-supplied run_command input to a shell. The default 0.0.0.0 bind exposes TCP port 8000, granting unauthenticated network clients command execution, arbitrary file access, and PTY shells.

CVSS severity9.3
Critical
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in Cua Computer Server before 0.3.42 allows remote attackers to execute arbitrary commands through its HTTP API. When CONTAINER_NAME is unset, the /cmd handler skips credential checks and dispatches attacker-supplied run_command input to a shell. The default 0.0.0.0 bind exposes TCP port 8000, granting unauthenticated network clients command execution, arbitrary file access, and PTY shells.

The record

CVE
CVE-2026-86121
Published
Sep 5, 2026
Updated
Sep 8, 2026
Vendor
Cua
Product
Cua Computer Server
Classifications
CWE-306, T1190, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 8, 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=0 <0.3.42

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Cua · Cua Computer Serverversion=0 <0.3.42

Published CVSS scores

9.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1190Exploit Public-Facing Application
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

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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