Regression in Cursor 3.20: Remote SSH Extension Host crashes with SIGSEGV on Ubuntu 18.04 (linux-legacy-x64)

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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

The Cursor 3.20 version can establish an SSH connection with Ubuntu 18.04 but cannot use the full IDE functions, such as Git. The remote host keeps restarting constantly. However, the Cursor 14 version has no such issues.

Steps to Reproduce

Use Cursor IDE to establish connection with Ubuntu 18.07 System

Operating System

Windows

Version Information

Version: 3.20.7 (system setup)
VS Code Extension API: 1.128.0
Commit: 979197d5570b168c034c634b3e21f2bea3ea5be0
Date: 2026-09-10T01:42:19.105Z
Layout: IDE
Build Type: Stable
Release Track: Nightly
Electron: 42.10.0
Chromium: 148.0.7778.280
Node.js: 24.18.1
V8: 14.8.178.38-electron.0
xterm.js: 6.1.0-beta.291
OS: Windows_NT x64 10.0.26200

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

4

Here is the log file. The problem has appeared in Cursor 3.15.

2026-09-10 15:33:16.507 [info] Extension host agent started.

2026-09-10 15:33:16.740 [info] [127.0.0.1][b90ddf4c][ManagementConnection] New connection established.

2026-09-10 15:33:16.753 [info] [127.0.0.1][6527654b][ExtensionHostConnection] New connection established.

2026-09-10 15:33:16.761 [info] Getting extensions control

2026-09-10 15:33:16.764 [info] [CursorProclistService] Config enabled feature (subsample every 10s; memoryPressureMonitorEnabled=true)

2026-09-10 15:33:18.319 [info] [127.0.0.1][6527654b][ExtensionHostConnection] <60992> Launched Extension Host Process.

2026-09-10 15:33:19.763 [error] Error getting extensions control manifest Timeout getting extensions control

2026-09-10 15:33:22.601 [info] [127.0.0.1][6527654b][ExtensionHostConnection] <60992> Extension Host Process exited with code: null, signal: SIGSEGV.

2026-09-10 15:33:22.603 [info] Cancelling previous shutdown timeout

2026-09-10 15:33:22.603 [info] Last EH closed, waiting before shutting down

2026-09-10 15:33:22.639 [error] [127.0.0.1][6527654b][ExtensionHostConnection] Unknown reconnection token (seen before).

2026-09-10 15:33:22.750 [info] [127.0.0.1][b6d804a2][ExtensionHostConnection] New connection established.

2026-09-10 15:33:22.772 [info] [127.0.0.1][b6d804a2][ExtensionHostConnection] <61279> Launched Extension Host Process.

2026-09-10 15:33:27.465 [info] [127.0.0.1][b6d804a2][ExtensionHostConnection] <61279> Extension Host Process exited with code: null, signal: SIGSEGV.

2026-09-10 15:33:27.465 [info] Cancelling previous shutdown timeout

2026-09-10 15:33:27.466 [info] Last EH closed, waiting before shutting down

2026-09-10 15:33:27.494 [error] [127.0.0.1][b6d804a2][ExtensionHostConnection] Unknown reconnection token (seen before).

2026-09-10 15:33:27.534 [info] [127.0.0.1][94572589][ExtensionHostConnection] New connection established.

2026-09-10 15:33:27.597 [info] [127.0.0.1][94572589][ExtensionHostConnection] <61349> Launched Extension Host Process.

2026-09-10 15:33:32.001 [info] [127.0.0.1][94572589][ExtensionHostConnection] <61349> Extension Host Process exited with code: null, signal: SIGSEGV.

2026-09-10 15:33:32.001 [info] Cancelling previous shutdown timeout

2026-09-10 15:33:32.001 [info] Last EH closed, waiting before shutting down

2026-09-10 15:33:32.032 [error] [127.0.0.1][94572589][ExtensionHostConnection] Unknown reconnection token (seen before).

2026-09-10 15:33:35.937 [info] [127.0.0.1][8ea2f69b][ExtensionHostConnection] New connection established.

2026-09-10 15:33:35.957 [info] [127.0.0.1][8ea2f69b][ExtensionHostConnection] <61718> Launched Extension Host Process.

2026-09-10 15:33:40.440 [info] [127.0.0.1][8ea2f69b][ExtensionHostConnection] <61718> Extension Host Process exited with code: null, signal: SIGSEGV.

2026-09-10 15:33:40.440 [info] Cancelling previous shutdown timeout

2026-09-10 15:33:40.440 [info] Last EH closed, waiting before shutting down

2026-09-10 15:33:40.481 [error] [127.0.0.1][8ea2f69b][ExtensionHostConnection] Unknown reconnection token (seen before).

8

Hey @zjx140,

This only affects the 3.20 Nightly builds; the current stable release is fine. Quickest fix: install the current stable Cursor from Cursor · Download (and set your update channel back to the default/stable track so it doesn’t pull you onto Nightly again), then reconnect - Cursor installs a fresh matching server for that version automatically, nothing to clean up on the host.

We’ve let the team know. If it still happens on stable, reply here and I’ll take another look.

10

Hey @zjx140,

Quick update on this one. The remote extension host crash loop on Ubuntu 18.04 that you hit with 3.20 has been fixed and is included in the current stable release (3.20.10+).

If you moved back to 3.19 in the meantime, it’s now safe to update to the latest stable and reconnect. Cursor installs a fresh matching server on the host automatically, so there’s nothing to clean up on the remote side.

Thanks for the report and the log. Let me know if you still see the restarts after updating!