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
EPSS: 0.006 (42.9th percentile) — read the EPSS interpretation.
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.
Affected products
- Anyscale Ray
- Anyscale, Inc Ray — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (issue-tracking, Patch, patch, Issue Tracking)
- disclosure@vulncheck.com (issue-tracking, Patch, patch, Issue Tracking)
- disclosure@vulncheck.com (release-notes, Product, Release Notes)
- disclosure@vulncheck.com (Exploit, vendor-advisory, Patch, Mitigation, Vendor Advisory)
- disclosure@vulncheck.com (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.