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CVE-2026-33017
CISA KEV
critical
CVSS 9.8
[KEV] Vulnerability in langflow (CVE-2026-33017)
Summary
vulnerability in langflow (CVE-2026-33017). Successful exploitation can lead to full system takeover. Exploitable via `POST /api/v1/build_public_tmp/{flow_id}/flow`. Listed in CISA KEV — actively exploited. Mitigation: upgrade to `1.9.0` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-33017** has been found in langflow.
Attackers can target a specific entry point like `POST /api/v1/build_public_tmp/{flow_id}/flow` over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
Note: CISA has officially confirmed this is **actively exploited in the wild**. Treat it with elevated urgency.
What to do: upgrade langflow to **1.9.0** or later.
If unsure, ask your IT team or search "langflow CVE-2026-33017" on the vendor's site.
CVE-2026-33017 (langflow) — CWE-306 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: POST /api/v1/build_public_tmp/{flow_id}/flow / GET /api/v1/auto_login / POST /api/v1/flows/ / POST /api/v1/build_public_tmp/{id}/flow
Patched: `1.9.0` — apply immediately
Listed in CISA KEV — actively exploited, treat as top priority.
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-306) exists in langflow. Attackers reach the vulnerable code path via `POST /api/v1/build_public_tmp/{flow_id}/flow` without authentication.
📍 Affected scope
langflow — . Attack surface: POST /api/v1/build_public_tmp/{flow_id}/flow / GET /api/v1/auto_login / POST /api/v1/flows/ / POST /api/v1/build_public_tmp/{id}/flow.
🔥 Severity
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover **Listed in CISA KEV** — actively exploited in the wild, treat as top priority.
🔧 How to fix
Update to **1.9.0**.
🛡️ 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 `POST /api/v1/build_public_tmp/{flow_id}/flow` 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.
Related past incidents Similar incidents extracted from past CVEs
A similar vulnerability in the Drupal CMS (CVE-2018-7600) allowed remote code execution.
If this happens at your company Expected impact per business scenario
📌 E-commerce platform
Unauthorized access to backend systems could lead to data theft or alteration.
📌 Internal business systems
Could allow external parties to manipulate critical business workflows.
📌 Publicly accessible portals
May result in defacement or dissemination of false information.
Recommended action
Ensure immediate software updates and authenticate all changes within the application.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify 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。
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3Hunt for indicators of compromise detect
grep 'POST /api/v1/build_public_tmp/{flow_id}/flow' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで `POST /api/v1/build_public_tmp/{flow_id}/flow` 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。
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4Consider incident declaration escalate
Notify SOC / on-callCISA KEV登録済 = 実環境で悪用が観測されている。Step 3 で兆候があればインシデント対応宣言、無くてもパッチ適用までWAF強化を最優先で。
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6Apply patch patch
Upgrade langflow to 1.9.0ステージング環境で 1.9.0 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 3 で見つけた異常検知の続報チェックを含めること。
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7Post-deployment verification verify
Replay attack against POST /api/v1/build_public_tmp/{flow_id}/flow 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 3 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":"1.9.0"}]}]
PyPI
langflow
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.0"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-33017
- advisory https://github.com/advisories/GHSA-rvqx-wpfh-mfx7
- package https://github.com/langflow-ai/langflow
- web https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0
- web https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx
- web https://github.com/langflow-ai/langflow/releases/tag/1.8.2
- web https://medium.com/@aviral23/cve-2026-33017-how-i-found-an-unauthenticated-rce-in-langflow-by-reading-the-code-they-already-dc96cdce5896
- web https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-33017
- web https://www.sysdig.com/blog/cve-2026-33017-how-attackers-compromised-langflow-ai-pipelines-in-20-hours
- web https://github.com/langflow-ai/langflow/pull/12160
- web https://github.com/langflow-ai/langflow/issues/12345
- web https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-33017
- web https://github.com/advisories/GHSA-vwmf-pq79-vjvx