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CVE-2026-42048
critical
CVSS 9.6
Path Traversal in langflow (CVE-2026-42048)
Summary
path traversal in langflow (CVE-2026-42048). Data can be tampered with by attackers. Exploitable via `DELETE /api/v1/knowledge_bases`. Mitigation: upgrade to `1.9.0` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-42048** has been found in langflow.
Attackers can target a specific entry point like `DELETE /api/v1/knowledge_bases` over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 9.6/10.
What to do: upgrade langflow to **1.9.0** or later.
If unsure, ask your IT team or search "langflow CVE-2026-42048" on the vendor's site.
CVE-2026-42048 (langflow) — CWE-22 / CVSS v3 9.6
Attack vector: remote (network-reachable) / no user interaction
Attack surface: DELETE /api/v1/knowledge_bases / `delete_knowledge_bases_bulk` / `kb_names`
Patched: `1.9.0` — 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
**Path traversal** (CWE-22) exists in langflow. Attackers reach the vulnerable code path via `DELETE /api/v1/knowledge_bases` without authentication.
📍 Affected scope
langflow — . Attack surface: DELETE /api/v1/knowledge_bases / `delete_knowledge_bases_bulk` / `kb_names`.
🔥 Severity
Severity: Critical (CVSS 9.6/10). Data can be tampered with by attackers
🔧 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 `DELETE /api/v1/knowledge_bases` 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 'DELETE /api/v1/knowledge_bases' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで `DELETE /api/v1/knowledge_bases` 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 1.9.0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 DELETE /api/v1/knowledge_bases 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"}]}]