What’s Vulnerable › Vulnerabilities

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

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-24 · updated 2026-10-25
• Weakness: CWE-502

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.

Affected products

• feast-dev feast: before 0.63.0 — fixed in 0.63.0

How to fix

Upgrade to a fixed version: feast-dev feast 0.63.0. Check the vendor advisory for mitigations.

References

• https://github.com/feast-dev/feast/commit/835cda8e2c1359f1f496ad72701dbd6a73bdb25a
• https://github.com/feast-dev/feast/releases/tag/v0.63.0
• https://huntr.com/bounties/d64b8111-180b-46ba-afa3-c877fda2ede6
• https://www.vulncheck.com/advisories/feast-unauthenticated-rce-via-applyfeatureview-grpc-deserialization
• https://access.redhat.com/errata/RHSA-2026:60520
• https://access.redhat.com/security/cve/CVE-2026-56121
• https://bugzilla.redhat.com/show_bug.cgi?id=2492229
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56121.json

Get alerted when CVE-2026-56121 or the next vulnerability affects your stack