OpenAI Codex CLI for Windows, macOS, and Linux and Codex Desktop for Windows and macOS misclassified certain PowerShell commands as safe because their command-safety parser interpreted PowerShell's stop-parsing token (--%) differently than PowerShell itself. If a user opens an attacker-prepared repository and Codex follows its instructions, Codex can run a file-writing Git command without requesting user approval. On macOS and Linux, exploitation additionally requires separately installed PowerShell Core (pwsh) to be invoked. If filesystem protections permit the write, the command can modify Codex's configuration. If Codex later loads the modified configuration, it can launch an attacker-controlled MCP server and execute code with the user's privileges, allowing it to read, change, or delete files accessible to that account. The approval bypass does not disable filesystem sandboxing; the default filesystem sandbox on macOS and Linux can prevent writes outside permitted locations.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

Upgrade Codex CLI to version 0.131.0 or later, Codex Desktop for macOS to application version 26.519.22136 or later, or Codex Desktop for Windows to application version 26.519.21041 (Microsoft Store package 26.519.2081.0) or later.


Workaround

Until updated, do not open or follow instructions from untrusted repositories. On macOS and Linux, keep filesystem sandboxing enabled.

References
History

Tue, 01 Sep 2026 22:00:00 +0000

Type Values Removed Values Added
Description OpenAI Codex CLI for Windows, macOS, and Linux and Codex Desktop for Windows and macOS misclassified certain PowerShell commands as safe because their command-safety parser interpreted PowerShell's stop-parsing token (--%) differently than PowerShell itself. If a user opens an attacker-prepared repository and Codex follows its instructions, Codex can run a file-writing Git command without requesting user approval. On macOS and Linux, exploitation additionally requires separately installed PowerShell Core (pwsh) to be invoked. If filesystem protections permit the write, the command can modify Codex's configuration. If Codex later loads the modified configuration, it can launch an attacker-controlled MCP server and execute code with the user's privileges, allowing it to read, change, or delete files accessible to that account. The approval bypass does not disable filesystem sandboxing; the default filesystem sandbox on macOS and Linux can prevent writes outside permitted locations.
Weaknesses CWE-150
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: OAI

Published:

Updated: 2026-09-01T17:06:45.647Z

Reserved: 2026-08-12T03:54:33.704Z

Link: CVE-2026-19591

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-01T18:17:40.260

Modified: 2026-09-01T21:03:04.987

Link: CVE-2026-19591

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses