EUVD-2026-292835

fkie_cve-2026-41272

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.0, the core security wrappers (secureAxiosRequest and secureFetch) intended to prevent Server-Side Request Forgery (SSRF) contain multiple logic flaws. These flaws allow attackers to bypass the allow/deny lists via DNS Rebinding (Time-of-Check Time-of-Use) or by exploiting the default configuration which fails to enforce any deny list. This vulnerability is fixed in 3.1.0.

GHSA-2x8m-83vc-6wv4 — Flowise: SSRF Protection Bypass (TOCTOU & Default Insecure)

Affected: npm: flowise, npm: flowise-components

### Summary The core security wrappers (secureAxiosRequest and secureFetch) intended to prevent Server-Side Request Forgery (SSRF) contain multiple logic flaws. These flaws allow attackers to bypass the allow/deny lists via DNS Rebinding (Time-of-Check Time-of-Use) or by exploiting the default configuration which fails to enforce any deny list.

### Details The flaws exist in `packages/components/src/httpSecurity.ts`.

Default Insecure: If process.env.HTTP_DENY_LIST is undefined, checkDenyList returns immediately, allowing all requests (including localhost).

DNS Rebinding (TOCTOU): The function performs a DNS lookup (dns.lookup) to validate the IP, and then the HTTP client performs a new lookup to connect. An attacker can serve a valid IP first, then switch to an internal IP (e.g., `127.0.0.1`) for the second lookup.

### PoC Ensure `HTTP_DENY_LIST` is unset (default behavior).

Use any node utilizing secureFetch to access `http://127.0.0.1`.

Result: Request succeeds.

#### Scenario 2: DNS Rebinding

Attacker controls domain attacker.com and a custom DNS server.

Configure DNS to return `1.1.1.1` (Safe IP) with TTL=0 for the first query.

Configure DNS to return `127.0.0.1` (Blocked IP) for subsequent queries.

Flowise validates `attacker.com` -> `1.1.1.1` (Allowed).

Flowise fetches `attacker.com` -> `127.0.0.1` (Bypass).

Run the following for manual verification

```ts // PoC for httpSecurity.ts Bypasses import * as dns from 'dns/promises';

// Mocking the checkDenyL…

WID-SEC-W-2026-1145 — Flowise: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Flowise ausnutzen, um beliebigen Programmcode auszuführen, um Sicherheitsvorkehrungen zu umgehen, um Informationen offenzulegen, und um Dateien zu manipulieren.

Most recent entries from all

EUVD-2026-292835

fkie_cve-2026-41272

GHSA-2x8m-83vc-6wv4 — Flowise: SSRF Protection Bypass (TOCTOU & Default Insecure)

WID-SEC-W-2026-1145 — Flowise: Mehrere Schwachstellen