CVE-2026-30860: Tencent Weknora RCE Vulnerability

CVE-2026-30860 Overview

CVE-2026-30860 is a critical SQL Injection vulnerability affecting Tencent WeKnora, an LLM-powered framework designed for deep document understanding and semantic retrieval. The vulnerability exists in the application's database query functionality where the validation system fails to recursively inspect child nodes within PostgreSQL array expressions and row expressions. This allows attackers to bypass SQL injection protections and achieve remote code execution on the database server.

Critical Impact

Unauthenticated attackers can bypass SQL injection protections by smuggling dangerous PostgreSQL functions inside array and row expressions, enabling arbitrary code execution on the database server with database user privileges.

Affected Products

• Tencent WeKnora versions prior to 0.2.12

Discovery Timeline

• 2026-03-07 - CVE-2026-30860 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-30860

Vulnerability Analysis

This vulnerability arises from incomplete input validation in WeKnora's database query functionality. While the application implements SQL injection protections, the validation system does not recursively inspect child nodes within PostgreSQL array expressions (e.g., ARRAY[...]) and row expressions (e.g., ROW(...)). This oversight creates a critical gap in the security controls.

Attackers can exploit this weakness by embedding malicious PostgreSQL functions within these expression types. Once the SQL injection protection is bypassed, the attacker can chain multiple PostgreSQL capabilities together—including large object operations and library loading functions—to escalate from SQL injection to full remote code execution on the underlying database server.

The vulnerability is classified under CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), commonly known as SQL Injection. What makes this vulnerability particularly severe is the ability to execute arbitrary code with the privileges of the database user, which could lead to complete system compromise.

Root Cause

The root cause of this vulnerability lies in the incomplete recursive validation of SQL query structures. The validation system correctly identifies and blocks dangerous SQL constructs at the top level but fails to traverse and validate nested expressions within PostgreSQL array and row constructs. This allows malicious payloads to be wrapped inside these expression types to evade detection.

Attack Vector

The attack is network-accessible and requires no authentication or user interaction, making it highly exploitable. An attacker can craft malicious requests to the WeKnora application's database query endpoints, embedding dangerous PostgreSQL functions within array or row expressions. The attack chain typically involves:

1. Bypassing SQL injection protections by wrapping payloads in array or row expressions
2. Utilizing PostgreSQL large object operations to write arbitrary data to the file system
3. Leveraging PostgreSQL's library loading capabilities (such as lo_import, lo_export, and CREATE FUNCTION ... LANGUAGE C) to load and execute malicious shared libraries
4. Achieving arbitrary code execution with the privileges of the PostgreSQL database user

The vulnerability can be exploited without authentication, significantly lowering the barrier for attackers.

Detection Methods for CVE-2026-30860

Indicators of Compromise

• Unusual database queries containing nested ARRAY[...] or ROW(...) expressions with suspicious function calls
• Evidence of PostgreSQL large object operations (lo_import, lo_export, lo_create) in query logs
• Unexpected shared library files appearing in PostgreSQL data directories
• Database user processes spawning child processes or making network connections

Detection Strategies

• Monitor database query logs for queries containing nested array or row expressions with dangerous function names
• Implement database activity monitoring to detect large object operations that deviate from normal application behavior
• Deploy web application firewall (WAF) rules to detect SQL injection attempts targeting PostgreSQL-specific syntax
• Use runtime application self-protection (RASP) solutions to identify SQL injection bypass attempts

Monitoring Recommendations

• Enable detailed PostgreSQL query logging and monitor for anomalous patterns
• Set up alerts for any use of lo_import, lo_export, or CREATE FUNCTION statements outside of expected administrative operations
• Monitor file system activity in PostgreSQL data directories for unexpected file creation
• Implement network monitoring to detect outbound connections from database server processes

How to Mitigate CVE-2026-30860

Immediate Actions Required

• Upgrade Tencent WeKnora to version 0.2.12 or later immediately
• Audit database logs for any indicators of exploitation
• Review database user privileges and apply principle of least privilege
• Restrict network access to the WeKnora application to trusted sources only

Patch Information

Tencent has addressed this vulnerability in WeKnora version 0.2.12. The patch implements recursive validation of child nodes within array and row expressions, closing the SQL injection bypass vector. Organizations should upgrade to this version as soon as possible.

For detailed patch information, refer to the GitHub Security Advisory.

Workarounds

• Implement network-level restrictions to limit access to the WeKnora application to trusted IP addresses only
• Deploy a web application firewall (WAF) with rules specifically designed to detect PostgreSQL-specific SQL injection patterns
• Restrict PostgreSQL database user privileges by removing access to large object operations and library loading functions where not required
• Consider temporarily disabling the affected database query functionality until the patch can be applied