CVE-2026-56121: Feast vulnerable to unsafe deserialization RCE in registry server via UDF proto
(updated )
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
- access.redhat.com/errata/RHSA-2026:60520
- access.redhat.com/security/cve/CVE-2026-56121
- bugzilla.redhat.com/show_bug.cgi?id=2492229
- github.com/advisories/GHSA-q63x-9pfm-mjx4
- github.com/feast-dev/feast/commit/835cda8e2c1359f1f496ad72701dbd6a73bdb25a
- github.com/feast-dev/feast/releases/tag/v0.63.0
- huntr.com/bounties/d64b8111-180b-46ba-afa3-c877fda2ede6
- nvd.nist.gov/vuln/detail/CVE-2026-56121
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56121.json
- www.vulncheck.com/advisories/feast-unauthenticated-rce-via-applyfeatureview-grpc-deserialization
Code Behaviors & Features
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