CVE-2026-41486: Ray Remote Code Execution Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mw35-8rx3-xf9r",
  "modified" : "2026-05-13T13:37:51Z",
  "published" : "2026-04-24T16:15:00Z",
  "aliases" : [ "CVE-2026-41486" ],
  "summary" : "Ray: Remote Code Execution via Parquet Arrow Extension Type Deserialization",
  "details" : "Ray Data registers custom Arrow extension types (`ray.data.arrow_tensor`, `ray.data.arrow_tensor_v2`, `ray.data.arrow_variable_shaped_tensor`) globally in PyArrow. When PyArrow reads a Parquet file containing one of these extension types, it calls `__arrow_ext_deserialize__` on the field's metadata bytes. Ray's implementation passes these bytes directly to `cloudpickle.loads()`, achieving arbitrary code execution during schema parsing, before any row data is read.\n\nIn May 2024, Ray fixed a related vulnerability in `PyExtensionType`-based extension types ([issue #41314](https://github.com/ray-project/ray/issues/41314), [PR #45084](https://github.com/ray-project/ray/pull/45084)). In July 2025, [PR #54831](https://github.com/ray-project/ray/pull/54831) introduced `cloudpickle.loads()` into the replacement extension types' deserialization path, reintroducing the same class of vulnerability.\n\n## Impact\n\n- **Affected versions**: Ray 2.49.0 through 2.54.0 (latest release as of March 2026). The vulnerable `_deserialize_with_fallback` function with `cloudpickle.loads()` was introduced in commit `f6d21db1a4` ([PR #54831](https://github.com/ray-project/ray/pull/54831), July 2025), first released in Ray 2.49.0.\n- **Affected configurations**: Any process that uses Ray Data and reads Parquet files. The extension types are registered globally in PyArrow, so all Parquet reads in the process are affected, including `ray.data.read_parquet()`, `pyarrow.parquet.read_table()`, `pandas.read_parquet()`, etc.\n- **Attacker prerequisites**: The attacker must place a crafted Parquet file where a Ray Data pipeline reads it. No authentication or cluster access is required. The Parquet file must contain a column with a `ray.data.arrow_tensor` (or v2, or variable-shaped) extension type name, which makes this a targeted attack against Ray Data users.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ray"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.49.0"
      }, {
        "fixed" : "2.55.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ray-project/ray/security/advisories/GHSA-mw35-8rx3-xf9r"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-41486"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ray-project/ray/pull/54831"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ray-project/ray/pull/62056"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ray-project/ray/commit/c02bd31ae31996805868baa446a131a8d304525f"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ray-project/ray"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ray-project/ray/releases/tag/ray-2.55.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502", "CWE-94" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-24T16:15:00Z",
    "nvd_published_at" : "2026-05-08T22:16:29Z"
  }
}