Ray — Deserialization (CVE-2026-41486)
Date: 2026-05
Affected: anyscale/ray
Attack vector: deserialization
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-41486
CWE: CWE-502
CWE-94
CVSS: 8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)

Ray is an AI compute engine. From version 2.54.0 to before version 2.55.0, 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. This issue has been patched in version 2.55.0.


Mitigations:

Architectural layers (MAESTRO):