CVE-2026-23842 is a denial-of-service vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) affecting the gunthercox ChatterBot library, a machine learning conversational dialog engine. Versions prior to 1.2.11 improperly manage database sessions and the SQLAlchemy connection pool. Specifically, when multiple concurrent invocations of the get_response() method occur, the connection pool can become exhausted because connections are not properly released or recycled. This exhaustion prevents further database interactions, causing the ChatterBot service to become unresponsive and unavailable. Recovery requires a manual restart of the service, as the connection pool remains depleted. The vulnerability can be exploited remotely without authentication or user interaction, increasing its risk profile. The CVSS v3.1 score is 7.5 (high), reflecting the ease of exploitation and significant impact on availability. No known public exploits have been reported yet, but the flaw poses a serious risk to any deployment of vulnerable ChatterBot versions, especially in high-concurrency environments. The fix was introduced in version 1.2.11, which properly manages database connections to prevent pool exhaustion.

For European organizations using ChatterBot versions earlier than 1.2.11, this vulnerability can cause denial-of-service conditions leading to prolonged unavailability of chatbot services. This disruption can affect customer support, automated communication, and other AI-driven dialog applications, potentially degrading user experience and operational efficiency. Industries relying heavily on conversational AI, such as e-commerce, finance, and public services, may face service interruptions impacting business continuity. Since the vulnerability does not compromise data confidentiality or integrity, the primary concern is availability. However, persistent outages could indirectly affect organizational reputation and customer trust. The lack of authentication or user interaction requirements means attackers can exploit the vulnerability remotely and at scale, increasing the risk of widespread service disruption across European deployments.

The primary mitigation is to upgrade all instances of gunthercox ChatterBot to version 1.2.11 or later, which includes fixes for proper database session and connection pool management. Organizations should audit their chatbot deployments to identify vulnerable versions and prioritize patching. Additionally, implement monitoring and alerting on database connection pool metrics to detect abnormal exhaustion patterns early. Rate limiting or throttling concurrent requests to the get_response() method can reduce the risk of resource exhaustion. Employing circuit breakers or fallback mechanisms in chatbot services can help maintain partial functionality during high load or attack conditions. Finally, ensure that deployment environments have robust logging to facilitate incident response and root cause analysis if service disruptions occur.