CVE-2026-55580Public exploit

Local command execution via insecure security defaults

Published Aug 25, 2026 · Updated Aug 25, 2026

OS command injection in sonirico mcp-shell before 0.6.0 allows local users to execute unrestricted commands through shell_exec. SecurityValidator.validateCommand returns success when Security.Enabled is false, while the Docker allowlist accepts interpreters that consume attacker-controlled arguments. Access to the local stdio MCP session is required; commands run with the mcp-shell process user's access to files, environment data, and processes.

CVSS severity8.6
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in sonirico mcp-shell before 0.6.0 allows local users to execute unrestricted commands through shell_exec. SecurityValidator.validateCommand returns success when Security.Enabled is false, while the Docker allowlist accepts interpreters that consume attacker-controlled arguments. Access to the local stdio MCP session is required; commands run with the mcp-shell process user's access to files, environment data, and processes.

The record

CVE
CVE-2026-55580
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
sonirico
Product
mcp-shell
Classifications
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

8.6GitHubCVSS:4.0/AV:L/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.

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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-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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