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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.86%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.6 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.86% probability · 56th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-502
- Affected
- anyscale/ray
- Source
- disclosure@vulncheck.com
References
- https://github.com/ray-project/ray/pull/63469Issue Tracking, Patch
- https://github.com/ray-project/ray/pull/63470Issue Tracking, Patch
- https://github.com/ray-project/ray/releases/tag/ray-2.56.0Product, Release Notes
- https://github.com/ray-project/ray/security/advisories/GHSA-hhrp-gw25-jr43Exploit, Mitigation, Patch, Vendor Advisory
- https://www.vulncheck.com/advisories/ray-unsafe-deserialization-rce-via-webdataset-readerThird Party Advisory
- https://github.com/ray-project/ray/security/advisories/GHSA-hhrp-gw25-jr43Exploit, Mitigation, Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.