Description

A component of the MongoDB extension for Visual Studio Code does not neutralize special characters in a connection string before that value is placed into a command line the extension composes for an integrated terminal. An unauthenticated remote unauthorized-user who persuades a developer to accept a user-supplied connection target, and then to open the extension's shell feature, can place characters of the unauthorized-user’s choosing into that command line. No privileges on the developer's machine are required, but several user actions are. The confirmation the developer sees does not display the supplied text.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.3",
  "pubDate": "2026-09-03T16:18:25.703Z",
  "pubdate": "2026-09-03T16:18:25.703Z",
  "executiveSummary": "The MongoDB extension for Visual Studio Code is susceptible to a command injection vulnerability stemming from improper input sanitization of connection strings. This flaw allows an unauthenticated remote attacker to influence the composition of command lines executed within the integrated terminal. By tricking a developer into accepting a malicious connection string and subsequently launching the extension's shell feature, an attacker can achieve arbitrary command execution on the host machine. The vulnerability is characterized by a failure to neutralize shell metacharacters before passing the input to the command-line interface. Although the attack requires multiple user-interaction steps—specifically the acceptance of the connection target and the manual invocation of the shell feature—the absence of visual validation for the injected string during the confirmation process significantly elevates the risk. Successful exploitation grants the attacker the execution context of the developer's VS Code instance, which may lead to unauthorized system access, data exfiltration, or further compromise of the local development environment.",
  "technicalDetails": "The root cause of this vulnerability is an improper neutralization of special characters, specifically shell metacharacters, within the connection string parameter used by the MongoDB extension for Visual Studio Code. When the extension constructs commands for the integrated terminal, it concatenates user-provided connection strings directly into the command line buffer without adequate sanitization or escaping mechanisms. This architectural oversight permits the injection of command separators (such as ';', '&&', or '|') or subshell execution syntax (e.g., $(...)) into the final command execution string.\nThe exploitation flow follows a multi-stage process initiated by an attacker: 1) The attacker provides a crafted connection string containing shell-injected payloads to a developer. 2) The developer is social-engineered into adding this connection target into the MongoDB VS Code extension. 3) Because the extension lacks a verification mechanism that displays the raw content of the connection string during the approval flow, the developer remains unaware of the embedded malicious instructions. 4) The developer subsequently interacts with the extension's shell feature. 5) The underlying implementation pulls the tainted string and passes it into the system's terminal process, triggering the execution of the attacker's payload within the context of the user's shell session.\nThis vulnerability effectively bypasses process isolation by leveraging the terminal integration as a proxy for command execution. Since the command is executed in the developer's VS Code integrated terminal, it inherits the permissions and environment variables of the VS Code process. The impact is significant, as it enables the execution of arbitrary commands, facilitating post-exploitation activities such as environment variable theft, credential harvesting, installation of persistent backdoors, or unauthorized modification of local source code. The attack does not require any pre-existing privileges on the host machine or authentication, relying entirely on the manipulation of the extension's input handling logic. The lack of input validation at the point of ingestion ensures that the malicious payload persists within the extension's configuration until it is invoked by the unsuspecting developer."
}