CVE-2026-56121
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.41%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 1.41% probability · 71th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-502
- Source
- disclosure@vulncheck.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.