{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 10.65.1"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "mcp-memory-service"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "10.65.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-49291"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-26T21:04:38Z",
    "nvd_published_at": "2026-06-19T19:16:36Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nThe HTTP MCP JSON-RPC endpoint at `/mcp` requires only OAuth `read` scope for all requests, then dispatches `tools/call` directly to handlers that include mutating tools. A read-only OAuth client can call `store_memory` and `delete_memory` through MCP even though the corresponding REST endpoints require `write` scope.\n\n## Technical Details\n\n`src/mcp_memory_service/web/api/mcp.py` declares `mcp_endpoint` with `user: AuthenticationResult = Depends(require_read_access)`. For `tools/call`, it extracts the requested tool name and arguments, then calls `handle_tool_call(storage, tool_name, arguments)` without passing the authenticated user or checking a per-tool required scope.\n\nThe MCP tool registry includes both read tools and write tools. In the same handler file, `store_memory` creates a `Memory` object and calls `storage.store(...)`, while `delete_memory` calls `storage.delete(content_hash)`. These operations are reachable with only the `read` scope.\n\nThe REST endpoint demonstrates the intended boundary: `POST /api/memories` uses `Depends(require_write_access)` and rejects a read-only token with 403 `insufficient_scope`.\n\n## Reproduction\n\n1. Enable OAuth and disable anonymous access.\n2. Generate a valid OAuth JWT with only `scope: read`.\n3. Confirm the REST write endpoint rejects it:\n\n```http\nPOST /api/memories\nAuthorization: Bearer \u003cread-only-token\u003e\nContent-Type: application/json\n\n{\"content\":\"rest denied control\"}\n```\n\nExpected and observed: HTTP 403 with `Required scope \u0027write\u0027 not granted`.\n\n4. Send the same read-only token to the MCP endpoint:\n\n```http\nPOST /mcp\nAuthorization: Bearer \u003cread-only-token\u003e\nContent-Type: application/json\n\n{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 1,\n  \"method\": \"tools/call\",\n  \"params\": {\n    \"name\": \"store_memory\",\n    \"arguments\": {\n      \"content\": \"mcp read scope stored this\",\n      \"tags\": [\"poc\"]\n    }\n  }\n}\n```\n\nObserved: HTTP 200 JSON-RPC success and the storage `store` sink is reached.\n\n5. A read-only token can also call `delete_memory` through MCP if it knows a content hash:\n\n```http\nPOST /mcp\nAuthorization: Bearer \u003cread-only-token\u003e\nContent-Type: application/json\n\n{\n  \"jsonrpc\": \"2.0\",\n  \"id\": 2,\n  \"method\": \"tools/call\",\n  \"params\": {\n    \"name\": \"delete_memory\",\n    \"arguments\": {\"content_hash\": \"\u003cknown_hash\u003e\"}\n  }\n}\n```\n\nObserved: HTTP 200 JSON-RPC success and the storage `delete` sink is reached.\n\n## Impact\n\nA client intended to be read-only can inject or delete memories through the MCP API. This can corrupt the memory database, influence future agent context, and destroy stored user memories without the OAuth `write` scope required by the REST API.\n\n## Affected Versions\n\nConfirmed present on current main commit `c99a922477df41f75a44db11182ae48a57311910` and latest release tag `v10.65.0` (`4eb4a62665589f9dd9f8c393afa32de434b4098a`).\n\n## Suggested Fix\n\nEnforce authorization per MCP tool at `tools/call` time. Require `write` for `store_memory` and `delete_memory`, keep `read` only for read-only tools, and add regression tests proving direct `tools/call` to mutating tools is rejected before the handler reaches storage when the caller has only `read` scope.",
  "id": "GHSA-2r68-g678-7qr3",
  "modified": "2026-06-26T21:04:38Z",
  "published": "2026-06-26T21:04:38Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/doobidoo/mcp-memory-service/security/advisories/GHSA-2r68-g678-7qr3"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49291"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/doobidoo/mcp-memory-service"
    },
    {
      "type": "WEB",
      "url": "https://pypi.org/project/mcp-memory-service/10.65.3"
    },
    {
      "type": "WEB",
      "url": "https://web.archive.org/web/20260508112116/https://github.com/doobidoo/mcp-memory-service"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "mcp-memory-service: OAuth read-only clients can write and delete memories through MCP tools/call"
}