{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-45018",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-05-08T16:58:28.895Z",
        "datePublished": "2026-08-25T19:18:46.439Z",
        "dateUpdated": "2026-08-25T19:33:30.993Z"
    },
    "containers": {
        "cna": {
            "title": "Chainlit: Command injection via MCP stdio transport allows unauthenticated remote code execution",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-78",
                            "lang": "en",
                            "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "HIGH",
                        "baseScore": 9.8,
                        "baseSeverity": "CRITICAL",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "HIGH",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/Chainlit/chainlit/security/advisories/GHSA-w3fx-mc44-mf6j",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/Chainlit/chainlit/security/advisories/GHSA-w3fx-mc44-mf6j"
                },
                {
                    "name": "https://github.com/Chainlit/chainlit/commit/0565fd0eccb915fce159929598b053ed79f6e0c9",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/Chainlit/chainlit/commit/0565fd0eccb915fce159929598b053ed79f6e0c9"
                },
                {
                    "name": "https://github.com/Chainlit/chainlit/blob/2.12.0/docs/security-advisory-2026-mcp.md#spl-2026-001--command-injection-via-mcp-stdio",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/Chainlit/chainlit/blob/2.12.0/docs/security-advisory-2026-mcp.md#spl-2026-001--command-injection-via-mcp-stdio"
                },
                {
                    "name": "https://github.com/Chainlit/chainlit/releases/tag/2.12.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/Chainlit/chainlit/releases/tag/2.12.0"
                }
            ],
            "affected": [
                {
                    "vendor": "Chainlit",
                    "product": "chainlit",
                    "versions": [
                        {
                            "version": ">= 2.4.0rc0, < 2.12.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-08-25T19:18:46.439Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Chainlit is a Python framework for building production-ready conversational AI applications. From 2.4.0rc0 until 2.12.0, Chainlit deployments with features.mcp.enabled set to true in .chainlit/config.toml expose the POST /mcp endpoint without requiring authentication. For stdio transport, the endpoint accepts a user-controlled fullCommand string. The validate_mcp_command() function in backend/chainlit/mcp.py checks only the executable name against config.features.mcp.stdio.allowed_executables and passes unchecked arguments to StdioServerParameters in backend/chainlit/server.py. Because npx supports the -c argument, an attacker can execute arbitrary shell commands with the privileges of the Chainlit process. If allowed_executables is unset, its None default is treated as allowing every executable. This issue is fixed in version 2.12.0."
                }
            ],
            "source": {
                "advisory": "GHSA-w3fx-mc44-mf6j",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/Chainlit/chainlit/security/advisories/GHSA-w3fx-mc44-mf6j",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-08-25T19:33:08.662498Z",
                                "id": "CVE-2026-45018",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-08-25T19:33:30.993Z"
                }
            }
        ]
    }
}