PraisonAI: SQL Injection via unvalidated table_prefix in 9 conversation store backends (incomplete fix for CVE-2026-40315)
The fix for [CVE-2026-40315](https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-x783-xp3g-mqhp) added input validation to SQLiteConversationStore only. Nine sibling backends — MySQL, PostgreSQL, async SQLite/MySQL/PostgreSQL, Turso, SingleStore, Supabase, SurrealDB — pass table_prefix straight into f-string SQL. Same root cause, same code pattern, same exploitation. 52 unvalidated injection points across the codebase.
postgres.py additionally accepts an unvalidated schema parameter used directly in DDL.
Severity
High — CWE-89 (SQL Injection)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N — 8.1
Exploitable in any deployment where table_prefix is derived from external input (multi-tenant setups, API-driven configuration, user-modifiable config files). Default config ("praison_") is not affected.
Details
The [CVE-2026-40315 fix](https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-x783-xp3g-mqhp) added this guard to sqlite.py:52:
```python
# sqlite.py — PATCHED
import re
if not re.match(r'^[a-zA-Z0-9_]*$', table_prefix):
raise ValueError("table_prefix must contain only alphanumeric characters and underscores")
```
The following backends perform the identical table_prefix → f-string SQL pattern without this guard:
| Backend | File | Line | Injection points |
| ---------------- | -------------------------------------------- | --------------- | ----------------------- |
| MySQL | persistence/conversation/mysql.py | 65 | 5 |
| PostgreSQL | persistence/conversation/postgres.py | 89 (+schema:88) | 10 |
| Async SQLite | persistence/conversation/async_sqlite.py | 43 | 13 |
| Async MySQL | persistence/conversation/async_mysql.py | 65 | 13 |
| Async PostgreSQL | persistence/conversation/async_postgres.py | 63 | 13 |
| Turso/LibSQL | persistence/conversation/turso.py | 66 | 9 |
| SingleStore | persistence/conversation/singlestore.py | 51 | 7 |
| Supabase | persistence/conversation/supabase.py | 68 | 9 |
| SurrealDB | persistence/conversation/surrealdb.py | 57 | 8 |
| Total | 9 backends | | 52 injection points |
Additionally, praisonai-agents/praisonaiagents/storage/backends.py:179 (SQLiteBackend) accepts table_name without validation.
PoC
```python
#!/usr/bin/env python3
"""
Demonstrates: sqlite.py rejects malicious table_prefix, mysql.py accepts it.
Run: python3 poc.py (no dependencies required)
"""
import re
payload = "x'; DROP TABLE users; --"
# ── SQLite (patched) ────────────────────────────────────────────────
try:
if not re.match(r'^[a-zA-Z0-9_]*$', payload):
raise ValueError("blocked")
print(f"[SQLite] FAIL — accepted: {payload}")
except ValueError:
print(f"[SQLite] OK — rejected malicious table_prefix")
# ── MySQL (unpatched) ───────────────────────────────────────────────
sessions_table = f"{payload}sessions"
sql = f"CREATE TABLE IF NOT EXISTS {sessions_table} (session_id VARCHAR(255) PRIMARY KEY)"
print(f"[MySQL] VULN — generated SQL:\n {sql}")
# ── PostgreSQL (unpatched — both table_prefix AND schema) ──────────
schema = "public; DROP SCHEMA data CASCADE; --"
sessions_table = f"{schema}.praison_sessions"
sql = f"CREATE SCHEMA IF NOT EXISTS {schema}"
print(f"[Postgres] VULN — schema injection:\n {sql}")
```
Output:
```
[SQLite] OK — rejected malicious table_prefix
[MySQL] VULN — generated SQL:
CREATE TABLE IF NOT EXISTS x'; DROP TABLE users; --sessions (session_id VARCHAR(255) PRIMARY KEY)
[Postgres] VULN — schema injection:
CREATE SCHEMA IF NOT EXISTS public; DROP SCHEMA data CASCADE; --
```
Vulnerable code (mysql.py, representative)
```python
# mysql.py:65-67 — NO validation
self.table_prefix = table_prefix # ← raw input
self.sessions_table = f"{table_prefix}sessions" # ← into identifier
self.messages_table = f"{table_prefix}messages"
# mysql.py:105 — straight into DDL
cur.execute(f"""
CREATE TABLE IF NOT EXISTS {self.sessions_table} (
session_id VARCHAR(255) PRIMARY KEY, ...
)
""")
```
Compare with the patched sqlite.py:52:
```python
# sqlite.py:52-53 — HAS validation
if not re.match(r'^[a-zA-Z0-9_]*$', table_prefix):
raise ValueError("table_prefix must contain only alphanumeric characters and underscores")
```
Impact
When table_prefix originates from untrusted input
