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

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-30 · updated 2026-07-06
Weakness: CWE-346

Description

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.

Affected products

FlowiseAI Flowise: before 3.1.2 — fixed in 3.1.2

How to fix

Upgrade to a fixed version: FlowiseAI Flowise 3.1.2. Check the vendor advisory for mitigations.

References

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