CVE-2026-19329Public exploit

Local command execution via unescaped model argument

Published Aug 9, 2026 · Updated Aug 9, 2026

Command injection in Codex MCP Server allows local users to execute OS commands through the ask tool's model argument. The ask handler appends the caller-controlled model value to Codex CLI flags without escaping, joins the arguments into a shell command, and passes it to execAsync. An attacker needs low-privilege local access to invoke the MCP tool; injected commands run with the server process's privileges.

CVSS severity5.3
Medium
EPSS probability0.62%
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 Codex MCP Server allows local users to execute OS commands through the ask tool's model argument. The ask handler appends the caller-controlled model value to Codex CLI flags without escaping, joins the arguments into a shell command, and passes it to execAsync. An attacker needs low-privilege local access to invoke the MCP tool; injected commands run with the server process's privileges.

The record

CVE
CVE-2026-19329
Published
Aug 9, 2026
Updated
Aug 9, 2026
Vendor
andreahaku
Product
Codex MCP Server
Classifications
CWE-77, CWE-74, T1059
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 9, 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=1ff521cc6cc57cfe56ddef946c644b8534771390

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

andreahaku · Codex MCP Serverversion=1ff521cc6cc57cfe56ddef946c644b8534771390

Published CVSS scores

5.3VulDBCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('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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