CVE-2026-56121 | Feast before 0.63.0 contains an unsafe deserialization vulne… | CVSS 9.8 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.

Metadata

CVE ID: CVE-2026-56121
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-18 19:15 UTC
Published: 2026-06-24 14:49 UTC
Last updated: 2026-06-24 16:03 UTC
Primary CWE: CWE-502
Deserialization of Untrusted Data
Vendor / Product: feast-dev / feast
Sources: cve.org · NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1

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

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: yes
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
feast-dev	feast	—	0 < 0.63.0

Weakness (CWE)

CWE	Source	Description
CWE-502	cna	Deserialization of Untrusted Data

CVSS scores (2)

Score	Severity	Version	Source	Vector
9.8	CRITICAL	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3	CRITICAL	4.0	cna	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

References (4)