CVE-2026-23842 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in chatterbot. A fix is available for chatterbot — see the affected versions and patch details below.
ChatterBot has Denial of Service via Database Connection Pool Exhaustion
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-23842.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-23842 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
chatterbotReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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.
Details
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
PoC
- Install ChatterBot version 1.2.10.
- Use the default database configuration (SQLite / SQLAlchemy).
- Run the following Python script to invoke concurrent requests:
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()
- Observe that the application becomes unresponsive and raises SQLAlchemy TimeoutError exceptions indicating exhaustion of the connection pool.
Impact
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | chatterbot | all versions | 1.2.11pip install --upgrade 'chatterbot==1.2.11' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for chatterbot, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update chatterbot to 1.2.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23842 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-23842 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-23842. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-23842 in your dependencies?
O3 Security finds CVE-2026-23842 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.