ruby-lsp vulnerability

Ruby LSP is an implementation of the language server protocol for Ruby. Several workspace-level settings in the Ruby LSP VS Code extension prior to version 0.10.4 could override the path to the Ruby executable, the version manager executables, or the Bundler `Gemfile` used at startup. A malicious repository containing a `.vscode/settings.json` could set these values to attacker-controlled targets. Opening and trusting the repository would then execute code with the privileges of the developer. The Ruby LSP gem and clients of the language server in other editors are not affected. Version 0.10.4 of the Ruby LSP VS Code extension fixes the issue.

Published 7 Aug 2026Updated 18 Sep 20261 sources
CVSS 5.4

What happened

Ruby LSP is an implementation of the language server protocol for Ruby. Several workspace-level settings in the Ruby LSP VS Code extension prior to version 0.10.4 could override the path to the Ruby executable, the version manager executables, or the Bundler `Gemfile` used at startup. A malicious repository containing a `.vscode/settings.json` could set these values to attacker-controlled targets. Opening and trusting the repository would then execute code with the privileges of the developer. The Ruby LSP gem and clients of the language server in other editors are not affected. Version 0.10.4 of the Ruby LSP VS Code extension fixes the issue.

Affected versions

ruby-lsp: < 0.10.4 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.