Windows elevated sandbox breaks node_repl and Browser Runtime
What version of the Codex App are you using (From “About Codex” dialog)?
26.527.31326
What subscription do you have?
Plus
What platform is your computer?
Microsoft Windows NT 10.0.26200.0 x64
What issue are you seeing?
When Codex Desktop is configured with:
[windows]
sandbox = "elevated"
the node_repl kernel fails before executing any user JavaScript.
Minimal test:
nodeRepl.write("ok");
fails with:
node_repl kernel exited unexpectedly
windows sandbox failed: spawn setup refresh
reason: stdout_eof
Because Browser Runtime depends on node_repl, browser automation is also unavailable.
What steps can reproduce the bug?
- Configure Codex Desktop:
sandbox_mode = "danger-full-access"
[windows]
sandbox = "elevated"
- Restart Codex Desktop.
- Execute:
nodeRepl.write("ok");
- Observe:
node_repl kernel exited unexpectedly
windows sandbox failed: spawn setup refresh
reason: stdout_eof
Additional confirmation:
Changing
[windows]
sandbox = "unelevated"
and restarting Codex Desktop makes node_repl work again.
What is the expected behavior?
node_repl should start successfully and execute JavaScript regardless of whether Windows sandbox mode is set to elevated or unelevated.
The following call should return successfully:
nodeRepl.write("ok");
Browser Runtime should remain operational because it depends on node_repl.
Additional information
Confirmed workaround:
[windows]
sandbox = "unelevated"
After switching to unelevated and restarting Codex Desktop:
nodeRepl.write(JSON.stringify({ ok: true, cwd: nodeRepl.cwd }));
returns:
{"ok":true,"cwd":"D:\\Antigravity\\IronHill"}
Browser Runtime also becomes functional again.
Additional observations:
- Codex-spawned environments contained both PATH and Path variables.
- PowerShell Env provider reported:
"An item with the same key has already been added."
- Attempting:
[mcp_servers.node_repl]
args = ["--disable-sandbox"]
did not affect the actual node_repl.exe command line.
A detailed diagnostic report is attached.
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3 Comments
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I can confirm the same issue after updating Codex Desktop on Windows. In my case, switching [windows] sandbox from "elevated" to "unelevated" fixed node_repl and restored the Chrome plugin.
Codex Desktop Windows
node_repl/ Chrome plugin failure after updateSummary
After updating Codex Desktop on Windows, the Chrome plugin and Browser Runtime failed because
node_replcould not start. The Chrome extension itself appeared installed and connected, but any attempt to use the Chrome plugin failed before reading tabs or page content.The issue was fixed locally by changing:
to:
and restarting Codex Desktop.
Environment
chrome@openai-bundledcomputer-use@openai-bundledLeo-MainhehggadaopoacecdllhhajmbjkdcmajgSymptoms
Minimal
node_replheartbeat failed:Observed error:
The same error occurred when trying to use the Chrome plugin to list Chrome tabs.
Local Logs
The local sandbox log contained:
This suggests the failing path was the Windows elevated sandbox setup refresh.
What Was Verified
.codex/plugins/cache/openai-bundled/chrome/26.601.21317..codex/plugins/cache/openai-bundled/computer-use/26.601.21317.node_replwas not valid.Workaround Applied
Created and ran:
The script backed up:
and changed:
After restarting Codex Desktop:
returned:
The Chrome plugin then successfully listed tabs and read a Gmail tab.
Impact
When
[windows] sandbox = "elevated"was active, the Chrome plugin and Browser Runtime were unusable because they depend onnode_repl. The issue appeared after updating Codex Desktop; it had worked on June 1, 2026 before the update.Related Public Reports
Suggested Upstream Request
Please confirm whether this is a known Codex Desktop Windows regression in the elevated sandbox setup path, and whether
[windows] sandbox = "unelevated"is currently a supported workaround. If elevated sandbox is expected to work, Codex Desktop should either repair the setup flow automatically or show a clearer actionable error whencodex-windows-sandbox-setup.exefails withos error 740.this is now fixed