CVE-2026-56121

critical

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.

References

https://www.vulncheck.com/advisories/feast-unauthenticated-rce-via-applyfeatureview-grpc-deserialization

https://huntr.com/bounties/d64b8111-180b-46ba-afa3-c877fda2ede6

https://github.com/feast-dev/feast/releases/tag/v0.63.0

https://github.com/feast-dev/feast/commit/835cda8e2c1359f1f496ad72701dbd6a73bdb25a

Details

Source: Mitre, NVD

Published: 2026-06-24

Updated: 2026-06-24

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 9.3

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

Severity: Critical