netlicensing-mcp: REST Path Traversal Bypasses Token Redaction

{
  "id": "65caac95af58a9997daa4639e62d08309b0d5bd2cdf8df8ffe6b1c82cd2161b5",
  "url": "https://osv.dev/vulnerability/GHSA-hxpf-9xvq-wph8",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "netlicensing-mcp: REST Path Traversal Bypasses Token Redaction",
    "summary": "### Summary The `netlicensing_get_product` MCP tool in `netlicensing-mcp` interpolates a caller-controlled `product_number` argument directly into a REST URL path without any validation. Passing `../token` as the product number causes `httpx` to normalize `/product/../token` into `/token`, silently redirecting the request to the NetLicensing token endpoint instead of the intended product endpoint. The response is then serialized through the generic `_wrap_json` wrapper rather than the token-specific `_wrap_json_token_read` wrapper, bypassing all APIKEY `number` and SHOP `shopURL` redaction. An authenticated MCP client can recover plaintext API key values that the token read tools intentionally mask, including admin-level APIKEY credentials. ### Details The vulnerability is a path traversal (CWE-22) that exploits the interaction between unsanitized string interpolation and `httpx`'s WHATWG URL normalization. **Source — `src/netlicensing_mcp/tools/products.py:22`** ```python async def get_product(product_number: str) -> dict: \"\"\"Get a single product by its number.\"\"\" return strip_output_fields(await nl_get(f\"/product/{product_number}\")) ``` `product_number` is inserted directly into the REST path with no validation. A value of `../token` produces the path `/product/../token`. **Sink — `src/netlicensing_mcp/client.py:143`** ```python async def nl_get(path: str, params: dict[str, str] | None = None) -> dict[str, Any]: client = _get_client() url = f\"{BASE_URL}{path}\" ... r = await",
    "evidence": "osv:GHSA-hxpf-9xvq-wph8",
    "products": [
      {
        "name": {
          "value": "netlicensing-mcp",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.1.8",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "0.0.6",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.1.0",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.1.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.1.2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.1.3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.1.4",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.1.5",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.1.6",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.1.7",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "GHSA-hxpf-9xvq-wph8",
      "aliases": [
        "CVE-2026-57496",
        "GHSA-hxpf-9xvq-wph8",
        "PYSEC-2026-3489"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0.1.8"
                }
              ]
            }
          ],
          "package": {
            "name": "netlicensing-mcp",
            "purl": "pkg:pypi/netlicensing-mcp",
            "ecosystem": "PyPI"
          },
          "versions": [
            "0.0.6",
            "0.1.0",
            "0.1.1",
            "0.1.2",
            "0.1.3",
            "0.1.4",
            "0.1.5",
            "0.1.6",
            "0.1.7"
          ],
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-hxpf-9xvq-wph8/GHSA-hxpf-9xvq-wph8.json"
          }
        }
      ],
      "modified": "2026-10-15T18:45:10.600088359Z",
      "provider": "osv",
      "references": [
        "https://github.com/Labs64/NetLicensing-MCP/security/advisories/GHSA-hxpf-9xvq-wph8",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-57496",
        "https://github.com/Labs64/NetLicensing-MCP/pull/6",
        "https://github.com/Labs64/NetLicensing-MCP/commit/b8fd0ea76d533202573eb24add9fb2fbd9331496",
        "https://github.com/Labs64/NetLicensing-MCP",
        "https://github.com/Labs64/NetLicensing-MCP/releases/tag/0.1.8",
        "https://github.com/pypa/advisory-database/tree/main/vulns/netlicensing-mcp/PYSEC-2026-3489.yaml"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-22"
        ],
        "severity": "CRITICAL",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-06-18T17:22:02Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-57496",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 335637,
  "published_at": "2026-06-18T17:22:02+00:00"
}