Windows elevated sandbox setup fails after Codex Desktop 26.609 update/reinstall: SetNamedSecurityInfoW failed: 5 on WindowsApps package directory

What version of the Codex App are you using (From “About Codex” dialog)?

26.609.30741

What subscription do you have?

pro

What platform is your computer?

Microsoft Windows NT 10.0.22631.0 x64

What issue are you seeing?

After Codex Desktop appears to have updated/reinstalled from a previously working 26.602.x setup to 26.609.x, Windows elevated Agent sandbox setup no longer works. The setup creates sandbox users and WFP/firewall rules successfully, but fails during the read ACL phase when trying to grant a read ACE on the Codex WindowsApps package app directory.

diagnostics.txt
previous_working_config_summary.txt
sandbox.2026-06-12.log
setup_error.json

What steps can reproduce the bug?

Title:
Windows elevated sandbox setup fails after Codex Desktop 26.609 update/reinstall: SetNamedSecurityInfoW failed: 5 on WindowsApps package directory

Summary:
After Codex Desktop appears to have updated/reinstalled from a previously working 26.602.x setup to 26.609.x, Windows elevated Agent sandbox setup no longer works. The setup creates sandbox users and WFP/firewall rules successfully, but fails during the read ACL phase when trying to grant a read ACE on the Codex WindowsApps package app directory.

Environment:

• OS: Windows
• Current Codex Desktop app version shown in config: 26.609.30741
• Current WindowsApps package path involved in failure:

C:\Program Files\WindowsApps\OpenAI.Codex_26.609.3341.0_x64__2p2nqsd0c76g0\app

• Previous working Codex app version shown in old config: 26.602.71036
• Previous CODEX_HOME:

E:\softwareData\AI\codex

• Current CODEX_HOME:

C:\Users\zzy\.codex

What changed:
Previously elevated Agent sandbox worked normally with a config containing:

[windows]
sandbox = "elevated"

After Codex Desktop appears to have updated/reinstalled, my config was regenerated under C:\Users\zzy\.codex and no longer contains [windows] sandbox = "elevated". Runtime paths also changed from the older AppData\Local\OpenAI\Codex\bin layout to a C:\Program Files\WindowsApps\OpenAI.Codex_... package path.

Current behavior:
Agent sandbox setup fails. The sandbox users and WFP/firewall rules appear to be created successfully, but setup fails during the read ACL phase.

Relevant log:
From C:\Users\zzy\.codex\.sandbox\sandbox.2026-06-12.log:

[2026-06-12T14:30:22.040676400+00:00] read-acl-only mode: applying read ACLs
[2026-06-12T14:30:22.046154700+00:00] granting read ACE to C:\Program Files\WindowsApps\OpenAI.Codex_26.609.3341.0_x64__2p2nqsd0c76g0\app for sandbox users
[2026-06-12T14:30:22.047102100+00:00] grant read ACE failed on C:\Program Files\WindowsApps\OpenAI.Codex_26.609.3341.0_x64__2p2nqsd0c76g0\app for sandbox_group: SetNamedSecurityInfoW failed: 5
[2026-06-12T14:30:22.117232900+00:00] read ACL run completed with errors: ["grant read ACE failed on C:\\Program Files\\WindowsApps\\OpenAI.Codex_26.609.3341.0_x64__2p2nqsd0c76g0\\app for sandbox_group: SetNamedSecurityInfoW failed: 5"]
[2026-06-12T14:30:22.117328600+00:00] setup error: read ACL run had errors

setup_error.json:

{
  "code": "helper_unknown_error",
  "message": "read ACL run had errors"
}

Additional checks:

• icacls on the target app directory shows WindowsApps-style protected ACLs. The directory is protected by SYSTEM/TrustedInstaller/package permissions, and BUILTIN\Administrators does not have write/ACL modification rights on the target directory.
• whoami /groups in the current Codex shell shows BUILTIN\Administrators as Group used for deny only and the integrity level is Medium, so the current process token is not elevated.

Expected behavior:
Elevated sandbox setup should continue to work after Codex Desktop update/reinstall, or the setup helper should avoid needing to modify ACLs inside the protected WindowsApps package directory. If elevated sandbox requires [windows] sandbox = "elevated", the update should preserve/migrate the setting or surface a clear setup prompt.

Actual behavior:
Sandbox setup fails with helper_unknown_error / read ACL run had errors because SetNamedSecurityInfoW returns Access Denied when trying to grant a read ACE on the Codex WindowsApps package app directory.

Possible regression:
This may be a regression between 26.602.71036 and 26.609.30741, or a regression caused by changing the installation/runtime layout from the previous AppData\Local\OpenAI\Codex\bin paths to the protected WindowsApps package directory.

Attachments included locally:

• current_config_sanitized.toml
• previous_working_config_summary.txt
• sandbox.2026-06-12.log
• setup_error.json
• diagnostics.txt

What is the expected behavior?

After Codex Desktop appears to have updated/reinstalled from a previously working 26.602.x setup to 26.609.x, Windows elevated Agent sandbox setup no longer works. The setup creates sandbox users and WFP/firewall rules successfully, but fails during the read ACL phase when trying to grant a read ACE on the Codex WindowsApps package app directory.

Additional information

diagnostics.txt
previous_working_config_summary.txt
sandbox.2026-06-12.log
setup_error.json