Pickle in the Middle – Hijacking Vertex AI Model Uploads for Cross-Tenant RCE

2026-06-16T20:51:37Z186ec975f471036ea6871c87fe62afbde85a471ccad66868f90612c49437f686
bucket-squattingcloud-securitycross-tenantgcsgoogle-cloudinsecure-deserializationpicklepythonrceremote-code-executionsdksupply-chainunit42vertex-aivulnerability

What happened

Unit 42 disclosed a vulnerability in the Google Vertex AI Python SDK where model uploads can be hijacked via bucket squatting and insecure deserialization (pickle), enabling cross-tenant remote code execution. An attacker who controls or precreates a storage bucket used during model upload can cause victim tenants to load malicious pickled objects, resulting in arbitrary code execution on Vertex AI workloads. This impacts model upload/serving flows that accept or load pickled artifacts.

Why it matters

A reviewed impact interpretation has not been published for this record.

Evidence and limitations

Source ID
paloalto_unit42
Record identifier
186ec975f471036ea6871c87fe62afbde85a471ccad66868f90612c49437f686
Enrichment time
2026-06-16T20:51:37Z
AI-assisted enrichment
Yes

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Record · Pickle in the Middle – Hijacking Vertex AI Model Uploads for Cross-Tenant RCE · Baitaphish