Vulnerability Report

CVE-2026-56277

Title: Flowise CORS Bypass

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-56277.

CWE Category CWE-346

Published Date Jun 30, 2026

Modified Date Jul 06, 2026

Exploit Status Not Found

Score 6.9 CVSS v4.0

Exploit Probability (EPSS)

0.14%

Vulnerability Summary

CVE-2026-56277: 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.

Impacted Vendors

flowiseai 1

Reference Links

https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m837-xvxr-vqwg https://www.vulncheck.com/advisories/flowise-hardcoded-cors-wildcard-in-tts-endpoint

CVSS v4.0

Source Entity [email protected]

Severity MEDIUM

6.9

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

N/A

RAW 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1