CVE Catalog

CVE-2026-45555

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.14%

4th percentile - higher than 4% of all known CVEs

Summary

Roslyn CodeLens MCP Server versions 0.0.9 through 1.17.0 contain a vulnerability where the get_diagnostics MCP tool loads and executes all DiagnosticAnalyzer assemblies referenced by the solution without any allowlist, signature check, or user confirmation. An attacker can place a malicious .csproj referencing an attacker-controlled DLL in a location the victim opens with the MCP server, leading to arbitrary code execution with the server's OS privileges.

Risk Assessment

The risk for the organization includes full compromise of the MCP server process, potentially leading to data theft, source code modification, or further attacks on the infrastructure.

Recommendation

Immediately update Roslyn CodeLens MCP Server to version 1.17.0 or later. Additionally, implement access controls for .csproj files and restrict the server process privileges.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS