{"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": {"cna": {"providerMetadata": {"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": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:chainlit:chainlit:2.12.0:*:*:*:*:*:*:*"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"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, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N", "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": ["technical-description"]}, {"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"}}}}