High severity · published Sep 12, 2026
CVE-2026-90535
Flowise before 3.1.4 Denial of Service via text-to-speech/abort
7.5
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FL
Flowise · FlowiseAI
before 3.1.4 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-90535
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-90535
Exploit
https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-xhxx-56g3-mx2r
Third Party Advisory
https://www.vulncheck.com/advisories/flowise-before-3.1.4-denial-of-service-via-text-to-speech-abort
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