CVE-2026-56121
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
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
CWEs
CWE-502
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.