{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-56121: Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-56121","status":"final","version":"1","initial_release_date":"2026-06-24T14:49:11.490Z","current_release_date":"2026-06-24T16:03:10.790Z","revision_history":[{"date":"2026-06-24T14:49:11.490Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-56121 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-56121"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-56121"},{"category":"external","summary":"Huntr Disclosure","url":"https://huntr.com/bounties/d64b8111-180b-46ba-afa3-c877fda2ede6"},{"category":"external","summary":"Release Notes","url":"https://github.com/feast-dev/feast/releases/tag/v0.63.0"},{"category":"external","summary":"Patch Commit","url":"https://github.com/feast-dev/feast/commit/835cda8e2c1359f1f496ad72701dbd6a73bdb25a"},{"category":"external","summary":"vulncheck.com","url":"https://www.vulncheck.com/advisories/feast-unauthenticated-rce-via-applyfeatureview-grpc-deserialization"}]},"product_tree":{"branches":[{"category":"vendor","name":"feast-dev","branches":[{"category":"product_name","name":"feast","branches":[{"category":"product_version_range","name":"<0.63.0","product":{"name":"feast-dev feast <0.63.0","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:feast-dev:feast:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-56121","title":"Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization","notes":[{"category":"description","text":"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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"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","baseScore":9.3,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 0.63.0.","product_ids":["CSAFPID-1"],"url":"https://github.com/feast-dev/feast/commit/835cda8e2c1359f1f496ad72701dbd6a73bdb25a"}]}]}