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.
CVSS
- Version: 4.0
- Vector: CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Base score: 8.6
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.86%
- Percentile among all scored CVEs: 57
- Score date: 10/5/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
🎯 ATT&CK techniques
How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.
- Exploitation
T1203Exploitation for Client Executionexecution85 % - Primary impact
T1059Command and Scripting Interpreterexecution90 %
Requiere interacción del usuario (UI:A) al suministrar un archivo tar malicioso a read_webdataset(). El pickle.loads() y torch.load() sin restricciones ejecutan código arbitrario en workers remotos.
Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.
🛡️ ATT&CK mitigations that cover these techniques
Affected technologies (1)
CWEs
- CWE-502
References
- https://github.com/ray-project/ray/pull/63469
- https://github.com/ray-project/ray/pull/63470
- https://github.com/ray-project/ray/releases/tag/ray-2.56.0
- https://github.com/ray-project/ray/security/advisories/GHSA-hhrp-gw25-jr43
- https://www.vulncheck.com/advisories/ray-unsafe-deserialization-rce-via-webdataset-reader
- https://github.com/ray-project/ray/security/advisories/GHSA-hhrp-gw25-jr43
Raw JSON (NVD)
Show
{
"id": "CVE-2026-57516",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-57516",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-07-01T17:53:01.380220Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 8.8,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 2.8
}
],
"cvssMetricV40": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 8.6,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "ACTIVE",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "HIGH",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "HIGH",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
}
}
]
},
"affected": [
{
"source": "disclosure@vulncheck.com",
"affectedData": [
{
"repo": "https://github.com/ray-project/ray",
"vendor": "Anyscale, Inc",
"product": "Ray",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "2.56.0",
"versionType": "semver"
}
],
"packageURL": "pkg:github/ray-project/ray",
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-01T17:16:37.390",
"references": [
{
"url": "https://github.com/ray-project/ray/pull/63469",
"tags": [
"Issue Tracking",
"Patch"
],
"source": "disclosure@vulncheck.com"
},
{
"url": "https://github.com/ray-project/ray/pull/63470",
"tags": [
"Issue Tracking",
"Patch"
],
"source": "disclosure@vulncheck.com"
},
{
"url": "https://github.com/ray-project/ray/releases/tag/ray-2.56.0",
"tags": [
"Product",
"Release Notes"
],
"source": "disclosure@vulncheck.com"
},
{
"url": "https://github.com/ray-project/ray/security/advisories/GHSA-hhrp-gw25-jr43",
"tags": [
"Exploit",
"Mitigation",
"Patch",
"Vendor Advisory"
],
"source": "disclosure@vulncheck.com"
},
{
"url": "https://www.vulncheck.com/advisories/ray-unsafe-deserialization-rce-via-webdataset-reader",
"tags": [
"Third Party Advisory"
],
"source": "disclosure@vulncheck.com"
},
{
"url": "https://github.com/ray-project/ray/security/advisories/GHSA-hhrp-gw25-jr43",
"tags": [
"Exploit",
"Mitigation",
"Patch",
"Vendor Advisory"
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"description": [
{
"lang": "en",
"value": "CWE-502"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"lastModified": "2026-07-14T22:17:23.287",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:anyscale:ray:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C4BB447B-4FCF-4A0F-B3BD-478B9B86E2D4",
"versionEndExcluding": "2.56.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "disclosure@vulncheck.com"
}