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    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-120492",
        "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "state": "PUBLISHED",
        "assignerShortName": "VulnCheck",
        "dateReserved": "2026-11-02T14:15:21.510Z",
        "datePublished": "2026-11-02T14:29:20.711Z",
        "dateUpdated": "2026-11-02T14:29:20.711Z"
    },
    "containers": {
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                "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
                "shortName": "VulnCheck",
                "dateUpdated": "2026-11-02T14:29:20.711Z"
            },
            "datePublic": "2026-11-02T00:00:00.000Z",
            "title": "Chainlit 2.12.0 SSRF via Semicolon Path Segment in MCP allowed_urls",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Chainlit 2.12.0 contains a server-side request forgery vulnerability that allows unauthenticated attackers to bypass path-scoped MCP allowed_urls entries because validate_mcp_url does not reject the semicolon character. Attackers can submit MCP URLs with '..;' segments to the /mcp endpoint, causing requests to paths outside the operator's grant on origins that strip semicolon path parameters."
                }
            ],
            "tags": [
                "unsupported-when-assigned"
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "Server-Side Request Forgery (SSRF)",
                            "cweId": "CWE-918",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "Chainlit",
                    "product": "Chainlit",
                    "defaultStatus": "unaffected",
                    "versions": [
                        {
                            "version": "2.12.0",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ],
                    "packageURL": "pkg:pypi/chainlit",
                    "repo": "https://github.com/Chainlit/chainlit"
                }
            ],
            "cpeApplicability": [
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                    "nodes": [
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                            "operator": "OR",
                            "negate": false,
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:a:chainlit:chainlit:2.12.0:*:*:*:*:*:*:*"
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                        "version": "4.0",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "NONE",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "LOW",
                        "subIntegrityImpact": "LOW",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 6.3,
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                        "attackVector": "NETWORK",
                        "attackComplexity": "HIGH",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "scope": "CHANGED",
                        "confidentialityImpact": "LOW",
                        "integrityImpact": "LOW",
                        "availabilityImpact": "NONE",
                        "baseScore": 5.4,
                        "baseSeverity": "MEDIUM"
                    }
                }
            ],
            "references": [
                {
                    "url": "https://github.com/Chainlit/chainlit/security/advisories/GHSA-hvfh-5mj3-5f3j",
                    "tags": [
                        "vendor-advisory"
                    ],
                    "name": "GitHub Security Advisory (GHSA-hvfh-5mj3-5f3j)"
                },
                {
                    "url": "https://github.com/Chainlit/chainlit/blob/2.12.0/backend/chainlit/mcp.py#L90-L177",
                    "tags": [
                        "technical-description"
                    ]
                },
                {
                    "url": "https://github.com/Chainlit/chainlit/blob/2.12.0/backend/chainlit/mcp.py#L199-L208",
                    "tags": [
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                    ]
                },
                {
                    "name": "VulnCheck Advisory: Chainlit 2.12.0 SSRF via Semicolon Path Segment in MCP allowed_urls",
                    "tags": [
                        "third-party-advisory"
                    ],
                    "url": "https://www.vulncheck.com/advisories/chainlit-2.12.0-ssrf-via-semicolon-path-segment-in-mcp-allowed-urls"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Gavin Blacklock",
                    "type": "finder"
                }
            ],
            "x_generator": {
                "engine": "vulncheck-endgame"
            }
        }
    }
}