{"id":"CVE-2026-9186","aliases":["EUVD-2026-71215","GHSA-gqfh-c8pj-64mr"],"status":"published","title":"Langflow is vulnerable to stored cross-site scripting and IP spoofing due to unsanitized Markdown rendering and untrusted proxy header trust","description":"IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to bypass localhost-only MCP configuration installation by spoofing X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config files (~/.cursor/mcp.json, etc.).","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00382,"percentile":0.32654,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-284"],"published":"2026-09-04T14:23:20Z","modified":"2026-09-08T21:45:27Z","products":[{"vendor":"ibm","product":"langflow oss"},{"vendor":"langflow","product":"langflow"}],"references":[{"url":"https://www.ibm.com/support/pages/node/7285646","tags":["vendor-advisory","patch","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9186"},{"url":"https://github.com/advisories/GHSA-gqfh-c8pj-64mr"}],"sources":{"cve":[{"id":"CVE-2026-9186","title":"Langflow is vulnerable to stored cross-site scripting and IP spoofing due to unsanitized Markdown rendering and untrusted proxy header trust","description":"IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to bypass localhost-only MCP configuration installation by spoofing X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config files (~/.cursor/mcp.json, etc.).","status":"published","published":"2026-09-04T14:23:20.117Z","modified":"2026-09-08T16:48:46.149Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T13:42:37.965383Z"}],"euvd":[{"id":"EUVD-2026-71215","description":"IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to bypass localhost-only MCP configuration installation by spoofing X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config files (~/.cursor/mcp.json, etc.).","status":"published","published":"2026-09-04T14:23:20Z","modified":"2026-09-08T16:48:46Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"updated_at":"2026-11-02T17:28:28.997972Z"}],"ghsa":[{"id":"GHSA-gqfh-c8pj-64mr","title":"IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to bypass localhost...","description":"IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to bypass localhost-only MCP configuration installation by spoofing X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config files (~/.cursor/mcp.json, etc.).","status":"published","published":"2026-09-04T15:36:17Z","modified":"2026-09-04T15:36:24Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T15:11:22.550434Z"}],"nvd":[{"id":"CVE-2026-9186","description":"IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to bypass localhost-only MCP configuration installation by spoofing X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config files (~/.cursor/mcp.json, etc.).","status":"published","published":"2026-09-04T15:17:50.86Z","modified":"2026-09-08T21:45:27.103Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T14:12:43.737972Z"}]}}