Every CVE Search/ Get API key

CVE-2026-56121

Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization

9.3 CriticalPublic exploitFix available

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
High
Integrity
High
Availability
High

Exploit likelihood

1.41%Up 0.7 points since Jun 25, 2026
90%50%10%1%

What each source reports

CVE List Score used 9.3

Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization

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.

Record
CVE-2026-56121
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
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1
8.8 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-502, CWE-502
Updated
2026-11-02
EUVDEUVD-2026-38801 9.3

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.

Record
EUVD-2026-38801
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
Updated
2026-11-02
GitHub AdvisoriesGHSA-q63x-9pfm-mjx4 9.3

Feast vulnerable to unsafe deserialization RCE in registry server via UDF proto

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.

Record
GHSA-q63x-9pfm-mjx4
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
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-502
Updated
2026-11-03
NVD 9.3

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.

Record
CVE-2026-56121
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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1
8.8 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-502
Updated
2026-11-02
OSV 9.3

Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization

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.

Record
CVE-2026-56121
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
Weakness
CWE-502
Updated
2026-11-02
OSVGHSA-q63x-9pfm-mjx4 9.3

Feast vulnerable to unsafe deserialization RCE in registry server via UDF proto

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.

Record
GHSA-q63x-9pfm-mjx4
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
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-502
Updated
2026-11-03

Affected products

Affected packages

Affected packages
PackageAffectedFixed
feast
PyPI
before 0.63.0
0.63.0
feast
PyPI
before 0.63.0, plus listed versions
0.1.00.1.0.post00.1.20.1.2.post00.1.2.post1
Show 45 moreShow less
0.10.00.10.10.10.1rc10.10.1rc30.10.20.10.30.10.40.10.50.10.60.10.70.10.80.11.00.12.00.12.10.13.00.14.00.14.10.15.00.15.10.16.00.16.10.17.00.18.00.18.10.19.00.19.10.19.20.19.30.19.40.20.00.20.10.20.20.21.00.21.10.21.20.21.30.22.00.22.10.22.20.22.30.22.40.23.00.23.10.23.20.24.0
0.63.0

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
SourceLinkDate
PoC in GitHubBiiTts/CVE-2026-56121-Feast-Unauth-RCE2026-06-30
PoC in GitHub0xdak/CVE-2026-56121_exploit2026-07-23
PoC in GitHubjoaovicdev/EXPLOIT-CVE-2026-561212026-08-30

History

History
RecordedChangedSources
affected, referencesOSV
affected, exploits, factsGitHub Advisories
aliases, publishedEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-56121 is a critical vulnerability (CVSS 9.3) in Feast-dev Feast, published June 24, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 1.41%, the 72nd percentile. Fixed in feast 0.63.0.

References

Show 6 moreShow less
This page doesn't list everything

Left out here: 97 versions. The JSON record has them.

MoveEnter Open