Remote-SSH: cursor-server segfault on Ubuntu 22.04 VM (node server-main.js), VS Code works fine

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Cursor Remote-SSH fails to connect to Ubuntu 22.04 VM. The remote cursor-server
crashes with Segmentation fault during startup. VS Code Remote-SSH works on the
same host with the same SSH config.

Steps to Reproduce

  1. Install Remote-SSH extension in Cursor
  2. Connect to Ubuntu VM via SSH
  3. Connection fails during remote server install/startup
    Manual reproduction on the Linux host (no Windows client needed):
BIN=/home/platon/.cursor-server/bin/linux-x64/e48ee6102a199492b0c9964699bf011886708ba0
"$BIN/node" "$BIN/out/server-main.js" \
  --start-server \
  --host=127.0.0.1 \
  --port=0 \
  --accept-server-license-terms \
  --enable-remote-auto-shutdown \
  --telemetry-level off

### Expected Behavior
Server bound to 127.0.0.1:xxxxx (IPv4)
Extension host agent listening on xxxxx
Segmentation fault (core dumped)



### Operating System
Linux

### Version Information
- **Client**: Cursor on Windows (version: [
Version: 3.7.27 (system setup)
VS Code Extension API: 1.105.1
Commit: e48ee6102a199492b0c9964699bf011886708ba0
Date: 2026-06-10T01:46:16.942Z
Layout: editor
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
xterm.js: 6.1.0-beta.256
OS: Windows_NT x64 10.0.22631])
- **Remote OS**: Ubuntu 22.04.5 LTS
- **glibc**: 2.35
- **Arch**: x86_64
- **CPU**: Intel Xeon Silver 4510 (VM, hypervisor flag present)
- **RAM**: 15Gi total, ~11Gi available
- **Remote Cursor Server**: 3.7.27
- **Server commit**: e48ee6102a199492b0c9964699bf011886708ba0
- **Bundled Node**: v20.18.2





### Additional Information
VS Code Remote-SSH connects to the same host with the same SSH config without issues.
Clearing ~/.cursor-server/extensions and ~/.cursor-server/data → still crashes
coredumpctl shows crash in bundled node running server-main.js:
PID: xxxxx (node)
Signal: 11 (SEGV)
Command Line: .../node .../out/server-main.js --start-server ...
Executable: .../node
Stack trace shows repeated frames at node + 0x1485d1c (possible recursion/stack issue).

Logs
Cursor Remote-SSH log (Windows): Output panel → "Remote - SSH", logLevel trace
Remote: /run/user/1000/cursor-remote-code.log.*
coredump: coredumpctl info output attached
Workaround
Use VS Code Remote-SSH on the same VM, or ssh host 'go test ...' from Windows.


### Does this stop you from using Cursor
No - Cursor works, but with this issue
5

Hey, thanks for the detailed report. Everything’s written up exactly the way we need.

This is a known bug on our side, not a misconfig. The root cause is that the remote cursor-server is still running on Node v20. Its V8 can crash with SEGV_PKUERR on VMs where the CPU advertises Intel Memory Protection Keys (PKU), but the hypervisor doesn’t fully virtualize them. VS Code doesn’t crash on the same host because it uses Node 22, which handles missing PKU correctly. Your Xeon Silver 4510 in a VM is exactly this scenario.

Workaround: edit the server startup script on the remote host:

~/.cursor-server/bin/linux-x64/<commit>/bin/cursor-server

and add this right before the last line:

export NODE_OPTIONS="--no-node-snapshot --jitless"

Two important notes:

  • --jitless disables the V8 JIT, so latency will be higher.
  • This change gets overwritten on every server update, so you’ll need to reapply it.

The same workaround is confirmed in a similar thread: Remote SSH: Segmentation fault (SEGV_PKUERR) on CPUs without PKU support

We know about the bug and it’s been reported internally, but there’s no fix timeline yet. I’ll post an update here as soon as we have one.

7

got it and thanks.