diff --git a/src/vs/workbench/api/node/extHostTunnelService.ts b/src/vs/workbench/api/node/extHostTunnelService.ts
index 5e0e5cafa32..45ed7f54f27 100644
--- a/src/vs/workbench/api/node/extHostTunnelService.ts
+++ b/src/vs/workbench/api/node/extHostTunnelService.ts
@@ -105,6 +105,9 @@ export function loadConnectionTable(stdout: string): Record<string, string>[] {
 }
 
 function knownExcludeCmdline(command: string): boolean {
+	if (command.length > 500) {
+		return false;
+	}
 	return !!command.match(/.*\.vscode-server-[a-zA-Z]+\/bin.*/)
 		|| (command.indexOf('out/server-main.js') !== -1)
 		|| (command.indexOf('_productName=VSCode') !== -1);