# CVE-2026-57516: Ray < 2.56.0 Unsafe Deserialization RCE via WebDataset Reader

> Attackers can achieve remote code execution in Ray workers by supplying a malicious tar archive to the WebDataset reader due to unsafe deserialization.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 1 Jul 2026
- **Updated:** 8 Oct 2026
- **Also known as:** ECHO-d8c2-64e4-5430, GHSA-hhrp-gw25-jr43, MINI-5jcp-mc9j-7799, MINI-f4wf-33fg-rvv4, PYSEC-2026-2273

## What is CVE-2026-57516?

CVE-2026-57516 is a high-severity unsafe deserialization vulnerability in Anyscale, Inc Ray, published on 1 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Ray prior to 2.56.0 contains an unsafe deserialization vulnerability in the WebDataset reader that allows attackers to achieve remote code execution by supplying a malicious tar archive to the read_webdataset() function. The _default_decoder() function in webdataset_datasource.py unconditionally calls pickle.loads() on tar entries with .pkl/.pickle extensions and torch.load() with weights_only=False on .pt/.pth entries, executing arbitrary code inside Ray remote workers on every worker that processes the malicious archive.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-57516?

3 open source packages ship an affected version, including ray. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ray` | PyPI | All versions | 2.56.0 |
| `ray` | PyPI | All versions | 2.56.0 |
| `ray` | PyPI | All versions | 2.56.0 |

Products: Anyscale Ray.

## How do I fix CVE-2026-57516?

Upgrade ray to 2.56.0 or later.

## Is CVE-2026-57516 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57516 exists.

## Other vulnerabilities in Anyscale, Inc Ray

- [CVE-2025-62593](https://insights.sbomify.com/CVE-2025-62593/): Ray-Project Ray Code Injection (critical 9.4, exploited in the wild)
- [CVE-2023-48022](https://insights.sbomify.com/CVE-2023-48022/): Ray has arbitrary code execution via jobs submission API (critical 9.8)
- [CVE-2023-48023](https://insights.sbomify.com/CVE-2023-48023/): Server-side request forgery in n/a (critical 9.1)
- [CVE-2026-41486](https://insights.sbomify.com/CVE-2026-41486/): Ray: Remote Code Execution via Parquet Arrow Extension Type Deserialization (high 8.9)
- [CVE-2026-32981](https://insights.sbomify.com/CVE-2026-32981/): Ray Dashboard <= 2.8.0 Path Traversal Leading to Local File Disclosure (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57516 and fix it if it is affected.

What it is: CVE-2026-57516 is a high-severity unsafe deserialization vulnerability in Anyscale, Inc Ray, published on 1 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57516 exists.

Affected packages and fixed versions:
- ray (PyPI): affected all versions; fixed in 2.56.0
- ray (PyPI): affected all versions; fixed in 2.56.0
- ray (PyPI): affected all versions; fixed in 2.56.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-57516/ (Markdown: https://insights.sbomify.com/CVE-2026-57516/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57516
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57516
- OSV: https://osv.dev/vulnerability/CVE-2026-57516

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57516/
Summaries are generated and may contain mistakes; the official description above is the record.