Ray < 2.56.0 Unsafe Deserialization RCE via WebDataset Reader
Anyscale, Inc · Ray
Official source article: GitHub GHSA-HHRP-GW25-JR43 ↗. Check the applicable product and release in the original source.
8.6HighCVSS 4.0
Recommended action
Within 7 days
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
1 current
CVE-2026-57516 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityray: Ray: Remote code execution via unsafe deserialization in WebDataset reader
15 known affected
The vendor explicitly identifies these products as affected by this CVE.
rhaii/vllm-gaudi-rhel9 as a component of Red Hat AI Inference Server
rhelai3/bootc-gaudi-rhel9 as a component of Red Hat Enterprise Linux AI (RHEL AI) 3
rhoai/odh-pipeline-runtime-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-pipeline-runtime-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-pipeline-runtime-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-pipeline-runtime-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-vllm-gaudi-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
Summary
A flaw was found in Ray. This unsafe deserialization vulnerability in the WebDataset reader allows a remote attacker to achieve arbitrary code execution. By supplying a specially crafted malicious tar archive to the read_webdataset() function, an attacker can trigger the unconditional deserialization of .pkl/.pickle or .pt/.pth entries, leading to the execution of arbitrary code within Ray remote workers.
Remediation
For more information visit https://access.redhat.com/errata/RHSA-2026:61627
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2026-41089
No EUVD known-exploited evidence
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.
EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
8.6 · CVSS 4.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available
01
What, why and how
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.
What
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.
Why
Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.
How
An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may execute code or commands in the affected security context.
What
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.
Why
Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.
How
An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No confirmed evidence
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.Reference recorded
A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
Likely attack path
a network path → Deserialization of Untrusted Data → execute code or commands in the affected security context
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
Active interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-502: Deserialization of Untrusted Data. The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIActiveUser interaction: A user must take a deliberate action for exploitation to succeed.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2026-41089Official EUVD mapping
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.
Official EUVD record ↗Cyber Security Agency of Singapore · English · CSA-SB-20260708Security Bulletin 8 July 2026 [PDF, 1MB]]
The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 8 July 2026 [PDF, 1MB]], published on 8 July 2026. Open the linked bulletin for the product, severity and reference information published in that issue.
Official advisory ↗JVN iPedia · Japanese · JVNDB-2026-022570anyscaleのrayにおける信頼できないデータのデシリアライゼーションに関する脆弱性
Ray 2.56.0未満のバージョンには、WebDatasetリーダーに安全でないデシリアライズの脆弱性が存在します。この脆弱性により、攻撃者は悪意のあるtarアーカイブをread_webdataset()関数に渡すことでリモートコード実行を達成できます。webdataset_datasource.py内の_default_decoder()関数は、.pkl/.pickle拡張子のtarエントリに対して無条件にpickle.loads()を呼び出し、.pt/.pthエントリに対してはweights_only=Falseの状態でtorch.load()を呼び出します。これにより、悪意のあるアーカイブを処理する各Rayリモートワーカー内で任意のコードが実行されます。
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Affected versionsThe structured affected or fixed version information changed.
Before
< 2.56.0 · Fixed: For more information visit https://access.redhat.com/errata/RHSA-2026:61627
After
Ray: < 2.56.0 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Affected versionsThe structured affected or fixed version information changed.
Before
Ray: < 2.56.0 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
After
Ray: < 2.56.0 · Fixed: For more information visit https://access.redhat.com/errata/RHSA-2026:61627
Affected versionsThe structured affected or fixed version information changed.
Before
rhaii/vllm-gaudi-rhel9 as a component of Red Hat AI Inference Server; rhelai3/bootc-gaudi-rhel9 as a component of Red Hat Enterprise Linux AI (RHEL AI) 3; rhoai/odh-pipeline-runtime-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-vllm-gaudi-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI) · Fixed: registry.redhat.io/rhaiis/vllm-cuda-rhel9@sha256:44224455142130c9594b4361fd21494c88244acb59b242f31ecb66019a5238dd_arm64 as a component of Red Hat AI Inference Server 3.2; registry.redhat.io/rhaiis/vllm-cuda-rhel9@sha256:e2a077acf23766ef900942296ce963a624d2c4b45ff22ca77cadeb94c051fd95_amd64 as a component of Red Hat AI Inference Server 3.2
After
rhaii/vllm-gaudi-rhel9 as a component of Red Hat AI Inference Server; rhelai3/bootc-gaudi-rhel9 as a component of Red Hat Enterprise Linux AI (RHEL AI) 3; rhoai/odh-pipeline-runtime-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-vllm-gaudi-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI) · Fixed: registry.redhat.io/rhaiis/vllm-cuda-rhel9@sha256:44224455142130c9594b4361fd21494c88244acb59b242f31ecb66019a5238dd_arm64 as a component of Red Hat AI Inference Server 3.2; registry.redhat.io/rhaiis/vllm-cuda-rhel9@sha256:e2a077acf23766ef900942296ce963a624d2c4b45ff22ca77cadeb94c051fd95_amd64 as a component of Red Hat AI Inference Server 3.2; registry.redhat.io/rhaiis/vllm-cuda-rhel9@sha256:73bbc4560132c4aaa9bbd608ce9560eeae7b30bcc8f014da460afa5622139372_amd64 as a component of Red Hat AI Inference Server 3.3; registry.redhat.io/rhaiis/vllm-cuda-rhel9@sha256:dc9887746020d299ecaac5d03221a8876b7024eeea79d82e1fb38afd955fb5c0_arm64 as a component of Red Hat AI Inference Server 3.3
Affected versionsThe structured affected or fixed version information changed.
Before
< 2.56.0 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
After
< 2.56.0 · Fixed: For more information visit https://access.redhat.com/errata/RHSA-2026:61627
Affected versionsThe structured affected or fixed version information changed.
Before
rhaii/vllm-gaudi-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server; rhelai3/bootc-gaudi-rhel9 as a component of Red Hat Enterprise Linux AI (RHEL AI) 3; rhoai/odh-pipeline-runtime-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-vllm-gaudi-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI)
After
rhaii/vllm-gaudi-rhel9 as a component of Red Hat AI Inference Server; rhelai3/bootc-gaudi-rhel9 as a component of Red Hat Enterprise Linux AI (RHEL AI) 3; rhoai/odh-pipeline-runtime-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-pipeline-runtime-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-vllm-gaudi-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-tensorflow-cuda-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-tensorflow-rocm-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI); rhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI) · Fixed: registry.redhat.io/rhaiis/vllm-cuda-rhel9@sha256:44224455142130c9594b4361fd21494c88244acb59b242f31ecb66019a5238dd_arm64 as a component of Red Hat AI Inference Server 3.2; registry.redhat.io/rhaiis/vllm-cuda-rhel9@sha256:e2a077acf23766ef900942296ce963a624d2c4b45ff22ca77cadeb94c051fd95_amd64 as a component of Red Hat AI Inference Server 3.2
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.