CVE-2026-5058Network attack vector

Unauthenticated code execution via unvalidated command allowlist

Published Apr 11, 2026 · Updated Apr 11, 2026

Command injection in Alexei Ledenev AWS MCP Server 1.3.0 allows remote attackers to execute arbitrary code through MCP requests. The allowed-commands handler uses a user-supplied string in a system call without proper validation, so the allowlist does not constrain the executed command. No authentication is required, and successful exploitation runs code with the MCP server process's privileges.

CVSS severity9.8
Critical
EPSS probability1.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Alexei Ledenev AWS MCP Server 1.3.0 allows remote attackers to execute arbitrary code through MCP requests. The allowed-commands handler uses a user-supplied string in a system call without proper validation, so the allowlist does not constrain the executed command. No authentication is required, and successful exploitation runs code with the MCP server process's privileges.

The record

CVE
CVE-2026-5058
Published
Apr 11, 2026
Updated
Apr 11, 2026
Vendor
Alexei Ledenev
Product
AWS MCP Server
Classifications
CWE-78, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 11, 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=1.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Alexei Ledenev · AWS MCP Serverversion=1.3.0

Published CVSS scores

9.8Zero Day InitiativeCVSS:3.0/AV:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
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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