[Eclipse Theia] Arbitrary Command Execution via Untrusted Workspace Task Definitions
Date: 2026-06
Affected: npm/@theia/workspace, npm/@theia/task, npm/@theia/debug
Attack vector: rce
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-44691
CWE: CWE-829

In Eclipse Theia versions prior to 1.69.0, custom task definitions in workspace files (e.g. .theia/tasks.json, .vscode/tasks.json) could be executed without requiring workspace trust. An attacker could craft a malicious repository that, when cloned and opened in Theia, leads to execution of arbitrary commands with the user's privileges. In combination with AI chat features and a workspace .theia/settings.json that disabled tool confirmation, this could be triggered automatically by sending a message in the AI chat.


Mitigations:

Architectural layers (MAESTRO):