Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization
Title source: cnaExploitation Summary
EIP tracks 1 public exploit for CVE-2026-56121. PoCs published by BiiTts.
AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-56121, demonstrating unauthenticated remote code execution in Feast's gRPC registry server via dill deserialization. The exploit leverages a malicious pickle payload in the user_defined_function.body field of an ApplyFeatureView request.
Description
Feast before 0.63.0 contains an unsafe deserialization vulnerability that allows unauthenticated or unauthorized attackers to achieve remote code execution by sending a crafted gRPC request to the registry server. The user_defined_function.body field of an OnDemandFeatureView spec is decoded from base64 and passed to dill.loads() before any authorization check is performed, enabling attackers to embed a malicious serialized Python object with an arbitrary __reduce__ method to execute OS commands as the feast service account.
Exploits (1)
This repository contains a functional exploit for CVE-2026-56121, demonstrating unauthenticated remote code execution in Feast's gRPC registry server via dill deserialization. The exploit leverages a malicious pickle payload in the user_defined_function.body field of an ApplyFeatureView request.
References (7)
Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H