Deserialization in Anyscale Ray
CVE-2026-57516
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.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.009 (57.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 57.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
- Anyscale Ray
- Anyscale, Inc Ray — versions 0
Weakness classification (CWE)
References
- Fix PR (1) (issue-tracking, Patch, patch, Issue Tracking)
- Fix PR (2) (issue-tracking, Patch, patch, Issue Tracking)
- Release Notes (release-notes, Product, Release Notes)
- GitHub Security Advisory (GHSA-hhrp-gw25-jr43) (vendor-advisory, Exploit, Patch, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/ray-unsafe-deserialization-rce-via-webdataset-read… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-57516?
- CVE-2026-57516 is a high-severity vulnerability in Anyscale Ray, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-07-01.
- How severe is CVE-2026-57516?
- High severity. CVSS v3 base score is 8.8 out of 10.