Remote code execution via default WebDataset deserialization
Published Jul 1, 2026 · Updated Jul 1, 2026
Unsafe deserialization in Anyscale Ray before 2.56.0 allows remote attackers to execute code by supplying a malicious WebDataset archive. The _default_decoder() function in webdataset_datasource.py passes .pkl and .pickle entries to pickle.loads() and .pt and .pth entries to torch.load() with weights_only=False. Exploitation requires a user or process to pass the attacker-controlled archive to read_webdataset(); the default decoder then runs code in each worker that processes it.
Summary
What happened
Unsafe deserialization in Anyscale Ray before 2.56.0 allows remote attackers to execute code by supplying a malicious WebDataset archive. The _default_decoder() function in webdataset_datasource.py passes .pkl and .pickle entries to pickle.loads() and .pt and .pth entries to torch.load() with weights_only=False. Exploitation requires a user or process to pass the attacker-controlled archive to read_webdataset(); the default decoder then runs code in each worker that processes it.
The record
- CVE
- CVE-2026-57516
- Published
- Jul 1, 2026
- Updated
- Jul 1, 2026
- Vendor
- Anyscale
- Product
- Ray
- Classifications
- CWE-502, CWE-94, T1204.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 1, 2026CVE publishedPublication date reported by the CVE source.
- Jul 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <2.56.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-hhrp-gw25-jr43 end-to-end reproductionproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo