CVE-2026-45555 Details
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.
A vulnerability in Roslyn CodeLens MCP Server versions 0.0.9 prior to 1.17.0 allows for untrusted execution of Roslyn analyzers. The 'get_diagnostics' MCP tool automatically loads and executes all referenced 'DiagnosticAnalyzer' assemblies from the target solution without any allowlist, signature verification, or user consent. This flaw enables an attacker to place a malicious project file (.csproj) that references a harmful DLL in a location accessed by the victim using the MCP server. Consequently, this could lead to arbitrary code execution within the server process, utilizing the operating system privileges of the server.
Update to Roslyn CodeLens MCP Server version 1.17.0 or later. If using an earlier version, disable the automatic loading of analyzers by setting 'includeAnalyzers' to false and manually reviewing any necessary analyzers before loading them.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed May 29, 2026CISA-ADP
Assessed May 29, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/MarcelRoozekrans/roslyn-codelens-mcp/security/advisories/GHSA-552p-8f74-6x7q | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/MarcelRoozekrans/roslyn-codelens-mcp/security/advisories/GHSA-552p-8f74-6x7q | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-94 | Improper Control of Generation of Code ('Code Injection') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| MarcelRoozekrans Roslyn CodeLens MCP Server | >= 0.0.9, < 1.17.0 (semver) |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 21, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 29, 2026 | CVE Modified | CISA-ADP |
| May 29, 2026 | New CVE Received | [email protected] |