{"id":"CVE-2026-120492","published":"2026-11-02T15:17:31.210","lastModified":"2026-11-02T15:17:31.360","description":"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.","cvssScore":5.4,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","cwes":["CWE-918"],"vendors":[],"products":[],"references":[{"url":"https://github.com/Chainlit/chainlit/blob/2.12.0/backend/chainlit/mcp.py#L199-L208","tags":[]},{"url":"https://github.com/Chainlit/chainlit/blob/2.12.0/backend/chainlit/mcp.py#L90-L177","tags":[]},{"url":"https://github.com/Chainlit/chainlit/security/advisories/GHSA-hvfh-5mj3-5f3j","tags":[]},{"url":"https://www.vulncheck.com/advisories/chainlit-2.12.0-ssrf-via-semicolon-path-segment-in-mcp-allowed-urls","tags":[]}],"exploitRefs":[{"url":"https://github.com/Chainlit/chainlit/blob/2.12.0/backend/chainlit/mcp.py#L199-L208","tags":[]},{"url":"https://github.com/Chainlit/chainlit/blob/2.12.0/backend/chainlit/mcp.py#L90-L177","tags":[]},{"url":"https://github.com/Chainlit/chainlit/security/advisories/GHSA-hvfh-5mj3-5f3j","tags":[]}],"hasPoc":true,"ai":null}