CVE-2026-56277 MEDIUM

CVE-2026-56277: Flowise - Hardcoded CORS Wildcard in TTS Endpoint

Vendor Flowise
Product Flowise
Weakness CWE-346 · Origin validation
Published June 30, 2026
Last update July 1, 2026

CVSS base score

6.9/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Flowise before 3.1.2 sets Access-Control-Allow-Origin to a hardcoded wildcard (*) on its text-to-speech (TTS) generation endpoint (packages/server/src/controllers/text-to-speech/index.ts), independent of the server's configured CORS policy. This bypasses the server's otherwise restrictive default CORS configuration (getCorsOptions()) and allows any webpage to make cross-origin requests that trigger TTS generation using stored credentials, enabling drive-by cross-origin credential abuse.

Key dates

02Disclosure timeline

June 30, 2026 CVE published
July 1, 2026 Record updated