{"id":"CVE-2026-23842","aliases":["GHSA-v4w8-49pv-mf72","PYSEC-2026-1244"],"title":"ChatterBot Vulnerable to Denial of Service via Database Connection Pool Exhaustion","summary":"ChatterBot Vulnerable to Denial of Service via Database Connection Pool Exhaustion","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"chatterbot","product":"chatterbot","ecosystem":"pip","affected":["chatterbot < 1.2.11"],"patched":["chatterbot 1.2.11"],"published":"2026-01-20","updated":"2026-07-07","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-v4w8-49pv-mf72","references":[{"url":"https://github.com/gunthercox/ChatterBot/security/advisories/GHSA-v4w8-49pv-mf72"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23842"},{"url":"https://github.com/gunthercox/ChatterBot/pull/2432"},{"url":"https://github.com/gunthercox/ChatterBot/commit/de89fe648139f8eeacc998ad4524fab291a378cf"},{"url":"https://github.com/gunthercox/ChatterBot"},{"url":"https://github.com/gunthercox/ChatterBot/releases/tag/1.2.11"},{"url":"https://github.com/user-attachments/assets/4ee845c4-b847-4854-84ec-4b2fb2f7090f"}],"tags":["osv","pip","exploit-available"],"epss":0.00549,"epssPercentile":0.44858,"ingestedAt":"2026-07-08T18:25:53.073Z","exploits":{"github":1,"githubRepos":["https://github.com/AdityaBhatt3010/CVE-2026-23842-Denial-of-Service-via-Database-Connection-Pool-Exhaustion-version-1.2.10"],"checkedAt":"2026-09-24T07:53:00.976Z"},"exploitAvailable":true,"slug":"CVE-2026-23842","body":"## Overview\n\n### Summary\nChatterBot 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.\n\n### Details\nChatterBot 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.\n\nWhen 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.\n\nThis 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.\n\nPoC Video: \nhttps://github.com/user-attachments/assets/4ee845c4-b847-4854-84ec-4b2fb2f7090f\n\n### PoC\n1. Install ChatterBot version 1.2.10.\n2. Use the default database configuration (SQLite / SQLAlchemy).\n3. Run the following Python script to invoke concurrent requests:\n\nfrom chatterbot import ChatBot\nimport threading\n\nbot = ChatBot(\"dos-test\")\n\ndef attack():\n    bot.get_response(\"hello\")\n\nthreads = []\nfor _ in range(30):\n    t = threading.Thread(target=attack)\n    t.start()\n    threads.append(t)\n\nfor t in threads:\n    t.join()\n\n4. Observe that the application becomes unresponsive and raises SQLAlchemy TimeoutError exceptions indicating exhaustion of the connection pool.\n\n### Impact\nThis 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.\n\nAll deployments of ChatterBot version 1.2.10 or earlier that allow concurrent access to the get_response() method are impacted.\n\n## Affected packages\n\n- `chatterbot < 1.2.11`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `chatterbot 1.2.11`","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":5022,"id":"CVE-2026-23842","ts":1788887229044,"field":"exploit_available","old":"false","new":"true"},{"seq":3905,"id":"CVE-2026-23842","ts":1788886360108,"field":"exploit_available","old":"true","new":"false"},{"seq":2727,"id":"CVE-2026-23842","ts":1788883025863,"field":"exploit_available","old":"false","new":"true"},{"seq":1756,"id":"CVE-2026-23842","ts":1788882429882,"field":"exploit_available","old":"true","new":"false"},{"seq":862,"id":"CVE-2026-23842","ts":1788881862896,"field":"exploit_available","old":"false","new":"true"}]}