CVE-2026-90535 Flowise before 3.1.4 Denial of Service via text-to-speech/abort
Unauthenticated attackers can disrupt active chatflow predictions for any user by exploiting missing ownership checks in the text-to-speech abort endpoint.
- 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-2026-90535?
CVE-2026-90535 is a medium-severity missing authorization vulnerability in Flowiseai Flowise, published on 12 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Flowise versions before 3.1.4 contain an unauthenticated denial of service vulnerability in the /api/v1/text-to-speech/abort endpoint that accepts user-supplied chatflowId and chatId without ownership verification. Attackers can terminate active chatflow predictions for any user by submitting requests with known chatflow and chat identifiers, causing targeted service disruption.
Weakness: CWE-862
Which versions are affected by CVE-2026-90535?
It affects 1 product.
Products include Flowiseai Flowise.
How do I fix CVE-2026-90535?
No fix has been published for CVE-2026-90535 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-90535 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90535 exists.
Other vulnerabilities in Flowiseai Flowise
- CVE-2025-71338 Flowise through 2.2.7 - Arbitrary File Write to Remote Code Execution via document-store API
- CVE-2026-40933 Flowise: Authenticated RCE Via MCP Adapters
- CVE-2025-61913 Flowise is vulnerable to arbitrary file read, arbitrary file write
- CVE-2025-59528 Flowise has Remote Code Execution vulnerability
- CVE-2026-52098 Code injection in n/a
Sources
Also known as GHSA-4xpg-6vjv-3v64, GHSA-xhxx-56g3-mx2r.