Vulnerability-Lookup

CVE-2026-23842 (GCVE-0-2026-23842)

Vulnerability from cvelistv5 – Published: 2026-01-19 18:39 – Updated: 2026-01-20 20:05

Title

ChatterBot has Denial of Service via Database Connection Pool Exhaustion

Summary

ChatterBot is a machine learning, conversational dialog engine for creating chat bots. 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. Version 1.2.11 fixes the issue.

Severity ?

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M

References

URL

Tags

	https://github.com/gunthercox/ChatterBot/security…	x_refsource_CONFIRM
	https://github.com/gunthercox/ChatterBot/pull/2432	x_refsource_MISC
	https://github.com/gunthercox/ChatterBot/commit/d…	x_refsource_MISC
	https://github.com/gunthercox/ChatterBot/releases…	x_refsource_MISC
	https://github.com/user-attachments/assets/4ee845…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	gunthercox	ChatterBot	Affected: < 1.2.11

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-23842

Vulnerability from fkie_nvd - Published: 2026-01-19 19:16 - Updated: 2026-01-19 19:16

Severity ?

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/gunthercox/ChatterBot/commit/de89fe648139f8eeacc998ad4524fab291a378cf
	security-advisories@github.com	https://github.com/gunthercox/ChatterBot/pull/2432
	security-advisories@github.com	https://github.com/gunthercox/ChatterBot/releases/tag/1.2.11
	security-advisories@github.com	https://github.com/gunthercox/ChatterBot/security/advisories/GHSA-v4w8-49pv-mf72
	security-advisories@github.com	https://github.com/user-attachments/assets/4ee845c4-b847-4854-84ec-4b2fb2f7090f

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "ChatterBot is a machine learning, conversational dialog engine for creating chat bots. 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. Version 1.2.11 fixes the issue."
    }
  ],
  "id": "CVE-2026-23842",
  "lastModified": "2026-01-19T19:16:04.510",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-01-19T19:16:04.510",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/gunthercox/ChatterBot/commit/de89fe648139f8eeacc998ad4524fab291a378cf"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/gunthercox/ChatterBot/pull/2432"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/gunthercox/ChatterBot/releases/tag/1.2.11"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/gunthercox/ChatterBot/security/advisories/GHSA-v4w8-49pv-mf72"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/user-attachments/assets/4ee845c4-b847-4854-84ec-4b2fb2f7090f"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

GHSA-V4W8-49PV-MF72

Vulnerability from github – Published: 2026-01-20 18:36 – Updated: 2026-01-20 18:36

Summary

ChatterBot Vulnerable to Denial of Service via Database Connection Pool Exhaustion

Details

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.

Severity ?

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.2.10"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "chatterbot"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-23842"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-01-20T18:36:17Z",
    "nvd_published_at": "2026-01-19T19:16:04Z",
    "severity": "HIGH"
  },
  "details": "### 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.",
  "id": "GHSA-v4w8-49pv-mf72",
  "modified": "2026-01-20T18:36:17Z",
  "published": "2026-01-20T18:36:17Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/gunthercox/ChatterBot/security/advisories/GHSA-v4w8-49pv-mf72"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23842"
    },
    {
      "type": "WEB",
      "url": "https://github.com/gunthercox/ChatterBot/pull/2432"
    },
    {
      "type": "WEB",
      "url": "https://github.com/gunthercox/ChatterBot/commit/de89fe648139f8eeacc998ad4524fab291a378cf"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/gunthercox/ChatterBot"
    },
    {
      "type": "WEB",
      "url": "https://github.com/gunthercox/ChatterBot/releases/tag/1.2.11"
    },
    {
      "type": "WEB",
      "url": "https://github.com/user-attachments/assets/4ee845c4-b847-4854-84ec-4b2fb2f7090f"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ChatterBot Vulnerable to Denial of Service via Database Connection Pool Exhaustion"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-23842 (GCVE-0-2026-23842)

FKIE_CVE-2026-23842

GHSA-V4W8-49PV-MF72

Summary

Details

PoC

Impact

Tags

Sightings

Nomenclature