CVE-2026-30859: Tencent Weknora Auth Bypass Vulnerability

CVE-2026-30859 Overview

CVE-2026-30859 is a broken access control vulnerability affecting Tencent WeKnora, an LLM-powered framework designed for deep document understanding and semantic retrieval. Prior to version 0.2.12, the application's database query tool fails to enforce proper tenant isolation, allowing any authenticated user to access sensitive data belonging to other tenants. This includes API keys, model configurations, and private messages stored in critical tables such as models, messages, and embeddings.

Critical Impact

Authenticated attackers can exploit this vulnerability to read sensitive cross-tenant data including API keys, model configurations, and private messages, potentially leading to complete compromise of other tenant environments.

Affected Products

• Tencent WeKnora versions prior to 0.2.12

Discovery Timeline

• 2026-03-07 - CVE-2026-30859 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-30859

Vulnerability Analysis

This vulnerability falls under the category of Broken Access Control (CWE-284), specifically involving improper tenant isolation in a multi-tenant SaaS environment. The WeKnora framework implements a database query tool that processes user requests without properly validating tenant boundaries. When an authenticated user executes queries against the database, the application fails to filter results based on the requesting tenant's identity, effectively exposing data from all tenants in the shared database infrastructure.

The vulnerability is particularly concerning in multi-tenant LLM deployments where sensitive information such as API keys for external services, custom model configurations, and private user conversations are stored. An attacker with valid user-level credentials in any tenant can leverage this flaw to enumerate and extract data belonging to other organizations or users sharing the same WeKnora instance.

Root Cause

The root cause of this vulnerability is the absence of tenant-scoped access controls in the database query layer. The application accepts authenticated requests but does not append tenant-specific filters to database queries executed against the models, messages, and embeddings tables. This architectural oversight allows horizontal privilege escalation, where users can access resources outside their authorized scope despite having valid authentication credentials.

Attack Vector

The attack vector is network-based and requires low-privilege authenticated access. An attacker must first obtain valid credentials for any tenant account within the WeKnora deployment. Once authenticated, the attacker can craft database queries through the query tool interface that target sensitive tables without tenant restrictions. The attack does not require user interaction and can be executed programmatically to systematically extract data from all tenants in the system.

The vulnerability mechanism involves the database query tool accepting authenticated requests and executing queries against shared tables without enforcing row-level security or tenant-based filtering. For detailed technical information, refer to the GitHub Security Advisory.

Detection Methods for CVE-2026-30859

Indicators of Compromise

• Unusual database query patterns accessing multiple tenant records from a single session
• Query logs showing access to models, messages, or embeddings tables with missing or mismatched tenant identifiers
• Anomalous data export volumes or API key enumeration attempts from authenticated sessions
• Authentication logs showing normal login patterns followed by cross-tenant data access attempts

Detection Strategies

• Implement database query logging and monitor for queries that return records with tenant IDs not matching the authenticated user's tenant
• Deploy application-level audit logging to track all data access operations in the query tool
• Configure SIEM rules to alert on database queries returning unusually large result sets or accessing sensitive columns across multiple tenants
• Monitor for bulk extraction patterns or sequential enumeration of sensitive data

Monitoring Recommendations

• Enable verbose logging for the WeKnora database query tool component
• Implement row-level access monitoring to detect cross-tenant data retrieval attempts
• Configure alerts for access to API key and model configuration fields by non-administrative users
• Regularly audit database access patterns for anomalies indicating data exfiltration

How to Mitigate CVE-2026-30859

Immediate Actions Required

• Upgrade Tencent WeKnora to version 0.2.12 or later immediately
• Conduct an audit of database access logs to identify any potential exploitation attempts
• Rotate all API keys and sensitive credentials stored within the affected WeKnora instance
• Notify affected tenants of potential data exposure and recommend credential rotation

Patch Information

Tencent has released version 0.2.12 of WeKnora which addresses this broken access control vulnerability by implementing proper tenant isolation in the database query tool. Organizations should upgrade immediately by following the instructions in the GitHub Security Advisory.

Workarounds

• Restrict network access to the WeKnora database query tool to trusted administrative users only until patching is complete
• Implement a reverse proxy with additional authorization checks that validate tenant scope before forwarding requests
• Temporarily disable the database query tool feature if it is not critical to operations
• Deploy database-level row security policies as an additional defense layer

# Upgrade WeKnora to patched version
pip install weknora>=0.2.12

# Verify installed version
pip show weknora | grep Version