CVE-2026-3959Public exploit

Local command execution via shell-interpolated tool arguments

Published Mar 11, 2026 · Updated Mar 11, 2026

OS command injection in WireMCP allows local users to execute arbitrary commands on the host through crafted MCP tool arguments. The capture and PCAP-analysis handlers interpolate interface, duration, and pcapPath values into tshark command strings passed to child_process.exec without neutralizing shell metacharacters. Access to an MCP client that can invoke those tools is required, and injected commands run with the WireMCP process privileges.

CVSS severity5.3
Medium
EPSS probability0.71%
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 WireMCP allows local users to execute arbitrary commands on the host through crafted MCP tool arguments. The capture and PCAP-analysis handlers interpolate interface, duration, and pcapPath values into tshark command strings passed to child_process.exec without neutralizing shell metacharacters. Access to an MCP client that can invoke those tools is required, and injected commands run with the WireMCP process privileges.

The record

CVE
CVE-2026-3959
Published
Mar 11, 2026
Updated
Mar 11, 2026
Vendor
0xKoda
Product
WireMCP
Classifications
CWE-77, CWE-78, T1059
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 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=7f45f8b2b4adeb76be8c6227eefb38533fdd6b1e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

0xKoda · WireMCPversion=7f45f8b2b4adeb76be8c6227eefb38533fdd6b1e

Published CVSS scores

1.9VulDBCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
4.3VulDBAV:L/AC:L/Au:S/C:P/I:P/A:P
5.3VulDBCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

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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