CVE-2026-10814: Weak Hash Implementation in Milvus Grantee ID Handler

Technical summary

CVE-2026-10814 stems from insufficient cryptographic practices in milvus/internal/metastore/kv/rootcoord/kv_catalog.go, specifically within the Grantee ID Hash Handler component. The code uses a weak hash function (CWE-327: Use of Broken or Risky Cryptographic Algorithm; CWE-328: Use of Insufficiently Random Values) to generate identifiers for access control grantees. An authenticated local attacker could potentially predict or collide hash outputs, undermining the integrity of role-based access controls. The CVSS 3.1 score of 4.5 (MEDIUM) reflects the requirement for local access and elevated privileges, combined with high attack complexity.

Business impact

Organizations running Milvus clusters face potential insider threats or privilege escalation scenarios. A compromised or malicious privileged user could manipulate grantee identifiers to gain unauthorized access to vector data or metadata, risking data confidentiality and integrity. In regulated environments handling sensitive embeddings (healthcare, financial services, personally identifiable information), this could lead to compliance violations and data breach liability.

Affected systems

Milvus versions up to and including 2.6.13 are affected. The vulnerability resides in the key-value metadata store layer used by the root coordinator component, which manages cluster-wide access controls. Any Milvus deployment using affected versions is in scope; the risk is highest in multi-tenant or shared cluster environments where access control isolation is critical.

Exploitability

Exploitation is difficult and requires local system access plus authenticated credentials with elevated privileges. An attacker must understand the hashing mechanism and have the ability to modify or interact with the key-value store. The attack complexity is rated as high, and no active exploitation has been reported in the wild as of the publication date. Public disclosure of the vulnerability has occurred, but the difficulty barrier limits opportunistic attacks.

Remediation

Apply the patch identified as commit 3d932f1c3e065351c4440c27abe1e6479752544d, which remediates the weak hash implementation in the Grantee ID Hash Handler. Verify the patch is incorporated into the next available Milvus release following version 2.6.13. Until patching is possible, restrict local access to Milvus cluster nodes and audit access control assignments to detect anomalies.

Patch guidance

Obtain and deploy the patch commit 3d932f1c3e065351c4440c27abe1e6479752544d to your Milvus installation. This update strengthens the cryptographic hash used for grantee identifiers. Test the patch in a non-production environment first, particularly if you maintain custom access control policies. After deployment, verify that existing grantee permissions remain consistent and that cluster operations resume normally. Consult the official Milvus advisory and release notes to confirm the patch's inclusion in a specific version release.

Detection guidance

Monitor Milvus logs and audit trails for unexpected changes to grantee assignments or access control entries, particularly modifications initiated by privileged accounts during unusual times. Check for patterns of hash collisions or repeated failed authentication attempts against vector collections. Use file integrity monitoring on the kv_catalog.go component and its compiled binary to detect tampering. If running Milvus in Kubernetes, inspect RBAC and network policies to restrict local access to cluster nodes.

Why prioritize this

Although the CVSS score is moderate (4.5), this vulnerability should be prioritized in environments where Milvus manages sensitive data or supports multi-tenant use cases. The high attack complexity and local access requirement lower the immediate risk for cloud-hosted managed Milvus services, but on-premise deployments and those with broad internal network access warrant prompt patching to prevent insider threats and privilege escalation.

Risk score, explained

The CVSS 3.1 score of 4.5 (MEDIUM) reflects: Attack Vector Local (AV:L), meaning the attacker must have local system access; Attack Complexity High (AC:H), indicating significant technical barriers and environmental conditions are required; Privileges Required (PR:L), demanding authenticated user credentials; no User Interaction (UI:N); unchanged Scope (S:U); and limited impact on Confidentiality, Integrity, and Availability (C:L/I:L/A:L). The score appropriately weights the insider threat model and high barrier to exploitation.

Frequently asked questions