Affected: MervinPraison PraisonAI

PraisonAI before 4.6.78 fails to validate the caller-controlled dimension argument in the PGVector and Cassandra knowledge-store create_collection() backends. Although schema, keyspace, and collection-name identifiers are validated, the dimension value (declared as int but not enforced at runtime) is interpolated directly into the vector column of the generated CREATE TABLE DDL. A caller able to influence collection-creation dimensions can pass a string such as '3); DROP TABLE tenant_secrets; --' to inject SQL/CQL tokens into the statement executed by the database driver.

Affected: PyPI: praisonai

# PGVector and Cassandra knowledge stores interpolate vector dimensions into DDL

## Summary

The PGVector and Cassandra knowledge-store backends validate SQL/CQL identifiers such as schema, keyspace, and collection names, but still insert the caller-controlled `dimension` argument directly into `CREATE TABLE` vector column declarations. A caller that can influence collection creation dimensions can append SQL/CQL tokens to the generated DDL executed by the database driver.

## Technical Details

The affected boundary is the vector-store collection creation API. The shared `KnowledgeStore.create_collection()` contract declares `dimension: int`, but Python type hints are not enforced at runtime. Backends that interpolate that value into DDL must validate the runtime value before constructing SQL/CQL.

`src/praisonai/praisonai/persistence/knowledge/pgvector.py` already treats DDL identifier interpolation as security-sensitive: `__init__()` calls `validate_identifier(schema, name="schema")`, and `_table_name()` calls `validate_identifier(collection, name="collection name")` before returning `f"{self.schema}.praison_vec_{collection}"`. However, `PGVectorKnowledgeStore.create_collection()` then executes:

```python cur.execute(f""" CREATE TABLE IF NOT EXISTS {table} ( id VARCHAR(255) PRIMARY KEY, content TEXT, content_hash VARCHAR(64), created_at DOUBLE PRECISION, metadata JSONB, embedding vector({dimension}) ) """) ```

No…