CVE-2026-56121 CRITICAL

CVE-2026-56121: Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization

Vendor Feast-Dev
Product feast
Weakness CWE-502 · Unsafe deserialization
Published June 24, 2026
Last update June 30, 2026

CVSS base score

9.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

June 24, 2026 CVE published
June 30, 2026 Record updated