CVE-2026-23842High· 7.5▾ MidnightPoC availableChatterBot Vulnerable to Denial of Service via Database Connection Pool Exhaustion
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 41.3 · likelihood 0.1 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Public exploit / PoC code seen in 1 source. Availability, not in-the-wild use.
Exploit-prediction probability, daily snapshots since Jul 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
0.5%
1 GitHub repo
0.5% → 0.5%
ChatterBot versions up to 1.2.10 are vulnerable to a denial-of-service condition caused by improper database session and connection pool management. Concurrent invocations of the get_response() method can exhaust the underlying SQLAlchemy connection pool, resulting in persistent service unavailability and requiring a manual restart to recover.
ChatterBot relies on SQLAlchemy for database access and uses a connection pool with default limits. The get_response() method does not enforce concurrency limits, rate limiting, or explicit session lifecycle controls.
When multiple threads concurrently invoke get_response(), database connections are rapidly consumed and not released in a timely manner. This leads to exhaustion of the SQLAlchemy QueuePool, causing subsequent requests to block and eventually fail with a TimeoutError.
This issue can be triggered without authentication in deployments where ChatterBot is exposed as a chatbot service, making it exploitable by remote attackers to cause denial of service.
PoC Video: https://github.com/user-attachments/assets/4ee845c4-b847-4854-84ec-4b2fb2f7090f
from chatterbot import ChatBot import threading
bot = ChatBot("dos-test")
def attack(): bot.get_response("hello")
threads = [] for _ in range(30): t = threading.Thread(target=attack) t.start() threads.append(t)
for t in threads: t.join()
This vulnerability allows an attacker to trigger a denial-of-service condition by exhausting the database connection pool. Once triggered, the chatbot becomes unresponsive to legitimate users and requires a manual restart to restore functionality.
All deployments of ChatterBot version 1.2.10 or earlier that allow concurrent access to the get_response() method are impacted.
chatterbot < 1.2.11Upgrade to a patched release:
chatterbot 1.2.11Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.