CVE-2026-19591Network attack vectorHinoki check available

Code execution via PowerShell stop-parsing interpretation mismatch

Published Sep 1, 2026 · Updated Sep 2, 2026

Command-safety bypass in OpenAI Codex CLI 0.72.0 through 0.130.0 and Codex Desktop allows remote attackers to execute code. The AST-backed command flattener treats PowerShell's --% stop-parsing form as an argv shape it can safely model, while PowerShell preserves the remaining native-command text. Exploitation requires a user to open the repository and Codex to follow its instructions; successful configuration writes can later launch an attacker-controlled MCP server with the user's file access.

CVSS severity8.8
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Command-safety bypass in OpenAI Codex CLI 0.72.0 through 0.130.0 and Codex Desktop allows remote attackers to execute code. The AST-backed command flattener treats PowerShell's --% stop-parsing form as an argv shape it can safely model, while PowerShell preserves the remaining native-command text. Exploitation requires a user to open the repository and Codex to follow its instructions; successful configuration writes can later launch an attacker-controlled MCP server with the user's file access.

The record

CVE
CVE-2026-19591
Published
Sep 1, 2026
Updated
Sep 2, 2026
Vendor
OpenAI
Product
Codex Desktop
Classifications
CWE-150, T1204, T1059.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 2, 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=260202.0859 <=26.513.31313
  2. Affected versionversion=26.304.38.0 <=26.513.4821.0
  3. Affected versionversion=26.304.38 <=26.513.40821

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenAI · Codex Desktopversion=260202.0859 <=26.513.31313; version=26.304.38.0 <=26.513.4821.0; version=26.304.38 <=26.513.40821
OpenAI · Codex CLIversion=0.72.0 <=0.130.0

Published CVSS scores

8.8CISA ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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.

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-150Improper Neutralization of Escape, Meta, or Control Sequences
T1204User Execution
T1059.001PowerShell

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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