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CVE-2026-105697 critical CVSS 9.9

OS Command Injection in langflow (CVE-2026-105697)

Summary

OS command injection in langflow (CVE-2026-105697). Successful exploitation can lead to full system takeover. Exploitable via PATCH /api/v2/mcp/servers/{server_name}. Mitigation: upgrade to 1.10.3 or later.

Original description

The description as published by the source.

Summary

Before Langflow 1.10.3, the MCP stdio transport launched whatever command / args a user put in an MCP server configuration, with no allowlist and (before 1.10.3) wrapped in bash -c "exec {command} ...". Any user able to reach the MCP server settings ("Settings → MCP Servers → Add MCP Server", POST/PATCH /api/v2/mcp/servers/{server_name}) or to build a flow with the MCP Tools component could add a "server" whose command is an arbitrary OS command (touch, rm -rf, a reverse shell, ...). The command runs on the Langflow host as the Langflow process user as soon as Langflow tries to connect to the server (listing servers, loading tools, running the flow) — even when the UI then reports that the stdio server failed to start.

With the default LANGFLOW_AUTO_LOGIN=true, GET /api/v1/auto_login hands out a token without credentials, so on an exposed instance running the default configuration this is reachable without an account. AUTO_LOGIN is documented as a development-only setting; with it disabled, any authenticated (non-admin) user can exploit it.

The issue was fixed in two steps and is fully fixed in Langflow 1.10.3 (and 1.11.0+):

  • 1.9.0 — #12290 added a command allowlist and argument/env validation to the REST model (MCPServerConfig), blocking the "Add MCP Server" vector reported here.
  • 1.10.3 — #14036 applied the same policy at the execution sink (lfx.base.mcp.util), including configs embedded in flows / tweaks and the final…

Source: NIST National Vulnerability Database NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-105697 has been found in langflow.
Attackers can target a specific entry point like PATCH /api/v2/mcp/servers/{server_name} over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.9/10.
What to do: upgrade langflow to 1.10.3 or later.
If unsure, ask your IT team or search "langflow CVE-2026-105697" on the vendor's site.

CVE-2026-105697 (langflow) — CWE-78 / CVSS v3 9.9
Attack vector: remote (network-reachable) / no user interaction
Attack surface: PATCH /api/v2/mcp/servers/{server_name} / GET /api/v1/auto_login / PATCH /api/v2/mcp/servers / command
Patched: 1.10.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

OS command injection (CWE-78) exists in langflow. Attackers reach the vulnerable code path via PATCH /api/v2/mcp/servers/{server_name}.

📍 Affected scope

Check the vendor advisory for the affected versions of langflow. Attack surface: PATCH /api/v2/mcp/servers/{server_name} / GET /api/v1/auto_login / PATCH /api/v2/mcp/servers / command.

🔥 Severity

Severity: Critical (CVSS 9.9/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 1.10.3.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual PATCH /api/v2/mcp/servers/{server_name} requests with malformed payloads or SQL meta-characters. Run grep -r 'langflow' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify 
    grep -r 'langflow' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で langflow を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Hunt for indicators of compromise detect 
    grep 'PATCH /api/v2/mcp/servers/{server_name}' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで PATCH /api/v2/mcp/servers/{server_name} への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。

  3. 3
    Apply patch patch 
    Upgrade langflow to 1.10.3

    ステージング環境で 1.10.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。

  4. 4
    Post-deployment verification verify 
    Replay attack against PATCH /api/v2/mcp/servers/{server_name} on staging to confirm patch closes the vector

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。

Affected packages

pip langflow
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.10.3"}]}]
pip langflow-base
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.10.3"}]}]
pip lfx
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.10.3"}]}]

References

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