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.).
Advisories
No advisories yet.
Fixes
Solution
IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.11.3 https://pypi.org/project/langflow/
Workaround
No workaround given by the vendor.
References
| Link | Providers |
|---|---|
| https://www.ibm.com/support/pages/node/7285646 |
|
History
Fri, 04 Sep 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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.). | |
| Title | Langflow is vulnerable to stored cross-site scripting and IP spoofing due to unsanitized Markdown rendering and untrusted proxy header trust | |
| First Time appeared |
Ibm
Ibm langflow Oss |
|
| Weaknesses | CWE-284 | |
| CPEs | cpe:2.3:a:ibm:langflow_oss:1.0.0:*:*:*:*:*:*:* cpe:2.3:a:ibm:langflow_oss:1.11.2:*:*:*:*:*:*:* |
|
| Vendors & Products |
Ibm
Ibm langflow Oss |
|
| References |
| |
| Metrics |
cvssV3_1
|
Projects
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Status: PUBLISHED
Assigner: ibm
Published:
Updated: 2026-09-04T14:23:20.117Z
Reserved: 2026-05-21T14:59:59.486Z
Link: CVE-2026-9186
No data.
Status : Received
Published: 2026-09-04T15:17:50.860
Modified: 2026-09-04T15:17:50.860
Link: CVE-2026-9186
No data.
OpenCVE Enrichment
Updated: 2026-09-04T16:30:06Z
Weaknesses