CVE-2026-73603 Flowise before 3.1.4 Credential Abuse via Text-to-Speech

Medium 6.3 Published 13 Aug 2026 Updated 14 Aug 2026

Unauthenticated attackers can abuse private chatflow credentials to generate unlimited text-to-speech audio, incurring costs on the owner's account.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-73603?

CVE-2026-73603 is a medium-severity missing authorization vulnerability in Flowiseai Flowise, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Flowise before 3.1.4 fails to validate chatflow visibility in the unauthenticated text-to-speech endpoint, allowing attackers to abuse private chatflow TTS credentials. Unauthenticated attackers can generate unlimited text-to-speech audio using stored OpenAI or ElevenLabs API keys by providing a valid chatflow UUID, incurring costs on the chatflow owner's account.

Weakness: CWE-862

Which versions are affected by CVE-2026-73603?

2 open source packages ship an affected version, including flowise. It affects 1 product.

Package	Affected	Fixed in
`flowise` npm	All versions	`3.1.4`
`flowise` npm	All versions	`3.1.4`

Products include Flowiseai Flowise.

How do I fix CVE-2026-73603?

Upgrade flowise to 3.1.4 or later.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-73603 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73603 exists.

All Flowiseai Flowise vulnerabilities

Sources

Also known as GHSA-8gj2-2cvc-6xx7, GHSA-w2r6-2jm7-ph5m.