CVE-2026-57516

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.

PUBLISHED Reserved 2026-06-24 | Published 2026-07-01 | Updated 2026-07-14 | Assigner VulnCheck

Problem types

Deserialization of Untrusted Data

Product status

Credits

jeremysommerfeld8910-cpu finder

shakevsky reporter

alexchenai reporter

SSJCorpSec reporter

thesecguy45 reporter

sfwani reporter

Rahul Karne reporter

References

github.com/...ct/ray/security/advisories/GHSA-hhrp-gw25-jr43 exploit

github.com/ray-project/ray/releases/tag/ray-2.56.0 (Release Notes) release-notes

github.com/...ct/ray/security/advisories/GHSA-hhrp-gw25-jr43 (GitHub Security Advisory (GHSA-hhrp-gw25-jr43)) vendor-advisory

github.com/ray-project/ray/pull/63469 (Fix PR (1)) patch issue-tracking

github.com/ray-project/ray/pull/63470 (Fix PR (2)) patch issue-tracking

www.vulncheck.com/...serialization-rce-via-webdataset-reader third-party-advisory

cve.org (CVE-2026-57516)

nvd.nist.gov (CVE-2026-57516)

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