{"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"}}}}