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CVE-2026-55450
critical
CVSS 9.3
Information Disclosure in langflow (CVE-2026-55450)
Summary
vulnerability in langflow (CVE-2026-55450). Risk of unauthorized operations or information disclosure. Exploitable via `POST /api/v1/upload/{flow_id}`. Mitigation: upgrade to `1.9.1` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-55450** has been found in langflow.
Attackers can target a specific entry point like `POST /api/v1/upload/{flow_id}` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 9.3/10.
What to do: upgrade langflow to **1.9.1** or later.
If unsure, ask your IT team or search "langflow CVE-2026-55450" on the vendor's site.
CVE-2026-55450 (langflow) — CWE-200 / CVSS v3 9.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: POST /api/v1/upload/{flow_id} / `flow_id` / `save_uploaded_file` / `get_flow`
Patched: `1.9.1` — 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
**information disclosure** (CWE-200) exists in langflow. Attackers reach the vulnerable code path via `POST /api/v1/upload/{flow_id}` without authentication.
📍 Affected scope
langflow — . Attack surface: POST /api/v1/upload/{flow_id} / `flow_id` / `save_uploaded_file` / `get_flow`.
🔥 Severity
Severity: Critical (CVSS 9.3/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **1.9.1**.
🛡️ 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/upload/{flow_id}` 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 (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
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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/upload/{flow_id}' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで `POST /api/v1/upload/{flow_id}` 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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6Apply patch patch
Upgrade langflow to 1.9.1ステージング環境で 1.9.1 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 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/upload/{flow_id} 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":"1.9.1"}]}]