{"id":"CVE-2026-45555","summary":"Roslyn CodeLens MCP Server: Untrusted Roslyn Analyzer Execution via get_diagnostics Leads to Arbitrary Code Execution","details":"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.","aliases":["GHSA-552p-8f74-6x7q"],"modified":"2026-07-23T03:56:12.170900627Z","published":"2026-05-29T12:54:59.678Z","database_specific":{"cwe_ids":["CWE-94"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45555.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45555.json"},{"type":"ADVISORY","url":"https://github.com/MarcelRoozekrans/roslyn-codelens-mcp/security/advisories/GHSA-552p-8f74-6x7q"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45555"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/marcelroozekrans/roslyn-codelens-mcp","events":[{"introduced":"56b6300607dabae7b2cc03653909c0ea89c69058"},{"fixed":"3ac5c0ca73a8228fc641da65e423f347dfeb9520"}],"database_specific":{"extracted_events":[{"introduced":"0.0.9"},{"fixed":"1.17.0"}],"source":"AFFECTED_FIELD"}}],"versions":["v1.16.0","v1.13.0","v1.15.0","v1.14.0","v1.12.0","v1.11.0","v1.10.0","v1.9.0","v1.8.0","v1.7.0","v1.6.0","v1.5.0","v1.4.0","v1.3.0","v1.2.1","v1.2.0","v1.1.7","v1.1.6","v1.1.5","v1.1.4","v1.1.3","v1.1.2","v1.1.1","v1.1.0","v1.0.15","v1.0.14","v1.0.13","v1.0.12","v1.0.11","v1.0.10","v1.0.9","v1.0.8","v1.0.7","v1.0.6","v1.0.5","v1.0.4","v1.0.3","v1.0.2","v1.0.1","v1.0.0","v0.0.15","v0.0.14","v0.0.13","v0.0.12","v0.0.11","v0.0.10","v0.0.9"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45555.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}