CVE-2026-19591
Summary
| CVE | CVE-2026-19591 |
|---|---|
| State | PUBLISHED |
| Assigner | OAI |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-01 18:17:40 UTC |
| Updated | 2026-09-02 19:17:16 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 8.8 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.003050000 probability, percentile 0.228950000 (date 2026-09-06)
Problem Types: CWE-150 | CWE-150 CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | OpenAI | Codex CLI | affected 0.72.0 0.130.0 semver | Windows, macOS, Linux |
| CNA | OpenAI | Codex CLI | unaffected 0.131.0 | Windows, macOS, Linux |
| CNA | OpenAI | Codex Desktop | affected 260202.0859 26.513.31313 custom | macOS |
| CNA | OpenAI | Codex Desktop | unaffected 26.519.22136 | macOS |
| CNA | OpenAI | Codex Desktop | affected 26.304.38 26.513.40821 custom | Windows |
| CNA | OpenAI | Codex Desktop | unaffected 26.519.21041 | Windows |
| CNA | OpenAI | Codex Desktop Microsoft Store Package | affected 26.304.38.0 26.513.4821.0 custom | Windows |
| CNA | OpenAI | Codex Desktop Microsoft Store Package | unaffected 26.519.2081.0 | Windows |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/openai/codex/pull/22643 | 8f4f43ab-ba69-4d92-aa1d-d772184d6fb7 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Emanuele Barbeno, Cyrill Bannwart, Yves Bieri, Lukasz D., and Urs Mueller of Compass Security (@compasssecurity). (en)
Additional Advisory Data
Solutions
CNA: 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.
Workarounds
CNA: Until updated, do not open or follow instructions from untrusted repositories. On macOS and Linux, keep filesystem sandboxing enabled.