FKIE_CVE-2026-45555

Vulnerability from fkie_nvd - Published: 2026-05-29 14:16 - Updated: 2026-07-21 12:10
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Summary
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.
References
security-advisories@github.comhttps://github.com/MarcelRoozekrans/roslyn-codelens-mcp/security/advisories/GHSA-552p-8f74-6x7q
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/MarcelRoozekrans/roslyn-codelens-mcp/security/advisories/GHSA-552p-8f74-6x7q
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "roslyn-codelens-mcp",
          "vendor": "MarcelRoozekrans",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.0.9, \u003c 1.17.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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\u0027s OS privileges. This vulnerability is fixed in 1.17.0."
    },
    {
      "lang": "es",
      "value": "Roslyn CodeLens MCP Server es un servidor MCP basado en Roslyn que proporciona inteligencia de c\u00f3digo sem\u00e1ntica para bases de c\u00f3digo .NET. Desde la versi\u00f3n 0.0.9 hasta la 1.17.0, la herramienta MCP get_diagnostics carga y ejecuta todos los ensamblados DiagnosticAnalyzer referenciados por la soluci\u00f3n objetivo sin ninguna lista de permitidos, verificaci\u00f3n de firma o confirmaci\u00f3n del usuario; includeAnalyzers tiene un valor predeterminado de true, por lo que no se requiere una aceptaci\u00f3n expl\u00edcita. Un atacante que puede colocar un archivo .csproj malicioso que referencia una DLL controlada por el atacante en una ubicaci\u00f3n que la v\u00edctima abre con el servidor MCP lograr\u00e1 la ejecuci\u00f3n de c\u00f3digo arbitrario en el proceso del servidor con los privilegios del sistema operativo del servidor. Esta vulnerabilidad est\u00e1 corregida en la versi\u00f3n 1.17.0."
    }
  ],
  "id": "CVE-2026-45555",
  "lastModified": "2026-07-21T12:10:00.090",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-45555",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-29T16:22:33.187069Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-29T14:16:30.113",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/MarcelRoozekrans/roslyn-codelens-mcp/security/advisories/GHSA-552p-8f74-6x7q"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/MarcelRoozekrans/roslyn-codelens-mcp/security/advisories/GHSA-552p-8f74-6x7q"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-94"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.