CVE-2026-55581Public exploitHinoki check available

Arbitrary command execution via permitted bash command mode

Published Aug 25, 2026 · Updated Aug 25, 2026

OS command injection in sonirico mcp-shell before 0.6.0 allows attackers to execute arbitrary commands inside its container. The shell_exec validator checks only the first token, permits the default-allowlisted /bin/bash, and passes its unchecked -c argument to exec.CommandContext. Access to the MCP tool is sufficient without authentication or custom configuration; commands run as mcpuser and can read or alter accessible data or interrupt the container.

CVSS severity8.4
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

OS command injection in sonirico mcp-shell before 0.6.0 allows attackers to execute arbitrary commands inside its container. The shell_exec validator checks only the first token, permits the default-allowlisted /bin/bash, and passes its unchecked -c argument to exec.CommandContext. Access to the MCP tool is sufficient without authentication or custom configuration; commands run as mcpuser and can read or alter accessible data or interrupt the container.

The record

CVE
CVE-2026-55581
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
sonirico
Product
mcp-shell
Classifications
CWE-183, CWE-1188, CWE-78, T1059.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=< 0.6.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

sonirico · mcp-shellversion=< 0.6.0

Published CVSS scores

8.4GitHubCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/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.

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No observations available

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

Weakness, pattern, technique

CWE-183Permissive List of Allowed Inputs
CWE-1188Initialization of a Resource with an Insecure Default
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Unix Shell

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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