---
cve: "CVE-2026-42048"
severity: "CRITICAL"
cvss: 9.6
epss: "0.6%"
vendor: "langflow-ai"
kev: false
exploited: false
published: "2026-05-12 18:17:23"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-25T05:00:24+01:00"
---

# CVE-2026-42048

> 9.6 CRITICAL · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2026-05-13 14:14:16
- CNA-CVSS: **9.6** (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Keine | good |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Schwachstellen-Klasse

- **CWE-22** — Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

## Angriffsmuster (CAPEC)

- [CAPEC-64 — Using Slashes and URL Encoding Combined to Bypass Validation Logic](https://capec.mitre.org/data/definitions/64.html) _(Severity: High)_
- [CAPEC-76 — Manipulating Web Input to File System Calls](https://capec.mitre.org/data/definitions/76.html) _(Severity: Very High)_
- [CAPEC-78 — Using Escaped Slashes in Alternate Encoding](https://capec.mitre.org/data/definitions/78.html) _(Severity: High)_
- [CAPEC-79 — Using Slashes in Alternate Encoding](https://capec.mitre.org/data/definitions/79.html) _(Severity: High)_
- [CAPEC-126 — Path Traversal](https://capec.mitre.org/data/definitions/126.html) _(Severity: Very High)_

## Patch verfügbar (OSV)

- a47f2ad17eb662e940c550cfccb64a87dddd7e0b (Commit)

## BSI-Hinweise (deutsch)

- [Langflow: Schwachstelle ermöglicht Denial of Service](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-1284) — _BSI-Einstufung: hoch_
  Ein entfernter, authentisierter Angreifer kann eine Schwachstelle in Langflow ausnutzen, um einen Denial of Service Angriff durchzuführen.

## Referenzen

- <https://github.com/langflow-ai/langflow/security/advisories/GHSA-9whx-c884-c68q>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-42048/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_