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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-45555

Roslyn CodeLens MCP Server: Untrusted Roslyn Analyzer Execution via get_diagnostics Leads to Arbitrary Code Execution

Description

Roslyn CodeLens MCP Server is a Roslyn-based MCP server providing semantic code intelligence for .NET codebases. From 0.0.9 to 1.17.0, the get_diagnostics MCP tool loads and executes all DiagnosticAnalyzer assemblies referenced by the target solution without any allowlist, signature check, or user confirmation; includeAnalyzers defaults to true, so no explicit opt-in is required. An attacker who can place a malicious .csproj referencing an attacker-controlled DLL in a location the victim opens with the MCP server will achieve arbitrary code execution in the server process with the server's OS privileges. This vulnerability is fixed in 1.17.0.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

MarcelRoozekrans roslyn-codelens-mcp

  • >= 0.0.9, < 1.17.0affected

References