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.
Original description
The description as published by the source.
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.0, Langflow is vulnerable to Path Traversal in the Knowledge Bases API (DELETE /api/v1/knowledge_bases). This occurs because user-supplied knowledge base names are concatenated directly into file paths without proper sanitization or boundary validation. An authenticated attacker can exploit this flaw to delete arbitrary directories anywhere on the server's filesystem, leading to data loss and potential service disruption. This vulnerability is fixed in 1.9.0.
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-2026-42048 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.
Path traversal (CWE-22) exists in langflow. Attackers reach the vulnerable code path via DELETE /api/v1/knowledge_bases.
Check the vendor advisory for the affected versions of langflow. Attack surface: DELETE /api/v1/knowledge_bases / delete_knowledge_bases_bulk / kb_names.
Severity: Critical (CVSS 9.6/10). Data can be tampered with by attackers.
Update to 1.9.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
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
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。 -
2Hunt 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。 -
3Apply 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 2 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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4Post-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 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
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com