Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-105698 medium CVSS 5.4

Vulnerability in langflow (CVE-2026-105698)

Summary

Vulnerability in langflow (CVE-2026-105698). Risk of unauthorized operations or information disclosure. Exploitable via POST /api/v1/build/{flow_id}/vertices. Mitigation: upgrade to 1.10.1 or later.

Original description

The description as published by the source.

Summary

Before Langflow 1.10.1, two deprecated but still-routed endpoints in the chat API did not check that the authenticated caller owns the flow referenced in the URL path:

  • POST /api/v1/build/{flow_id}/vertices (retrieve_vertices_order)
  • POST /api/v1/build/{flow_id}/vertices/{vertex_id} (build_vertex)

Any authenticated user who knows (or obtains) another user's flow_id could load that user's private flow graph, enumerate its vertex IDs, and build (execute) individual vertices of it, receiving the vertex results in the response.

Both routes are declared with deprecated=True, include_in_schema=False, so they do not appear in the OpenAPI docs, but they remained registered on the router. The Langflow UI no longer calls them (it uses POST /api/v1/build/{flow_id}/flow), so they are only reachable by direct HTTP requests.

The issue is fixed in Langflow 1.10.1 (langflow-base 0.10.1) by #13153.

Details

In affected versions, both handlers go straight to the graph loader:

  • retrieve_vertices_order (src/backend/base/langflow/api/v1/chat.py, lines 81-159 in 1.9.1) only required authentication via dependencies=[Depends(get_current_active_user)]. The user was never injected into the handler, and the flow was loaded with build_graph_from_db(flow_id=flow_id, ...).
  • build_vertex (chat.py, lines 320-491 in 1.9.1) receives current_user, but only uses it for variable resolution (`use…

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-2026-105698 has been found in langflow.
Attackers can target a specific entry point like POST /api/v1/build/{flow_id}/vertices over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: upgrade langflow to 1.10.1 or later.
If unsure, ask your IT team or search "langflow CVE-2026-105698" on the vendor's site.

CVE-2026-105698 (langflow) — CWE-639 / CVSS v3 5.4
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/v1/build/{flow_id}/vertices / POST /api/v1/build/{flow_id}/vertices/{vertex_id} / POST /api/v1/build/{flow_id}/flow / POST /api/v1/build/{victim_flow_id}/vertices
Patched: 1.10.1 — apply immediately
Workaround: If upgrading is not immediately possible, block POST /api/v1/build/*/vertices and POST /api/v1/build/*/vertices/* (and GET /api/v1/build/*/*/stream) at a reverse proxy.
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

A vulnerability (CWE-639) exists in langflow. Attackers reach the vulnerable code path via POST /api/v1/build/{flow_id}/vertices.

📍 Affected scope

Check the vendor advisory for the affected versions of langflow. Attack surface: POST /api/v1/build/{flow_id}/vertices / POST /api/v1/build/{flow_id}/vertices/{vertex_id} / POST /api/v1/build/{flow_id}/flow / POST /api/v1/build/{victim_flow_id}/vertices.

🔥 Severity

Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 1.10.1.

🛡️ Workaround

Workaround: If upgrading is not immediately possible, block POST /api/v1/build/*/vertices and POST /api/v1/build/*/vertices/* (and GET /api/v1/build/*/*/stream) at a reverse proxy.

🔍 Detection

Search webserver/proxy logs for unusual POST /api/v1/build/{flow_id}/vertices 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 'POST /api/v1/build/{flow_id}/vertices' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで POST /api/v1/build/{flow_id}/vertices 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 temporary workaround mitigate 
    If upgrading is not immediately possible, block `POST /api/v1/build/*/vertices` and `POST /api/v1/build/*/vertices/*` (and `GET /api/v1/build/*/*/stream`) at a reverse proxy.

    パッチが適用されるまでの応急処置として、If upgrading is not immediately possible, block POST /api/v1/build/*/vertices and POST /api/v1/build/*/vertices/* (and GET /api/v1/build/*/*/stream) at a reverse proxy. を実施。回避策の副作用 (機能低下) を確認した上で。

  4. 4
    Apply patch patch 
    Upgrade langflow to 1.10.1

    ステージング環境で 1.10.1 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。

  5. 5
    Post-deployment verification verify 
    Replay attack against POST /api/v1/build/{flow_id}/vertices 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":"1.10.1"}]}]
pip langflow-base
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.10.1"}]}]

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details