How severe is CVE-2026-41486?

No CVSS score has been assigned to CVE-2026-41486 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-41486?

CVE-2026-41486 affects the following packages: ray (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-41486?

Update ray to 2.55.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41486 is resolved across your whole dependency graph.

How do I detect CVE-2026-41486 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ray, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-41486 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2026-41486 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-41486 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-41486?

CVE-2026-41486 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 41th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-41486?

CVE-2026-41486 is classified as Code Injection (CWE-94), Deserialization of Untrusted Data (CWE-502). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-41486 published, and has it been updated?

CVE-2026-41486 was published on May 8, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

CVE-2026-41486 — ray

Fix: ray-project/ray@c02bd31

CVE-2026-41486 is a Code Injection vulnerability in ray. A fix is available for ray — see the affected versions and patch details below.

Ray: Remote Code Execution via Parquet Arrow Extension Type Deserialization

Also known asGHSA-mw35-8rx3-xf9rPYSEC-2026-2272PYSEC-2026-2296

Published

May 8, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-41486.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs41th percentile — riskier than 41% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐍ray

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

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.

In May 2024, Ray fixed a related vulnerability in PyExtensionType-based extension types (issue #41314, PR #45084). In July 2025, PR #54831 introduced cloudpickle.loads() into the replacement extension types' deserialization path, reintroducing the same class of vulnerability.

Impact

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, July 2025), first released in Ray 2.49.0.
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.
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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`ray`	≥ 2.49.0&&< 2.55.0	2.55.0`pip install --upgrade 'ray==2.55.0'`

Affected Products

1 product · 1 configurations

Application

rayanyscale

1 version

2.54.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ray, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ray to 2.55.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41486 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

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. In May 2024, Ray fixed a related vulnerability in `PyExtensionType`-based extension types ([issue #41314](https://github.com/ray-p

O3 Security · Impact-Aware SCA

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