Auth bypass in Flowiseai Flowise
CVE-2026-90535
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (41.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/FlowiseAI/Flowise/security/advisories/GHSA-xhxx-56g3-mx2r (Exploit, vendor-advisory, Vendor Advisory)
- www.vulncheck.com/advisories/flowise-before-3.1.4-denial-of-service-via-text-to… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-90535?
- CVE-2026-90535 is a high-severity vulnerability in Flowiseai Flowise, classified under Missing Authorization. CVSS score: 7.5/10. Published 2026-09-12.
- How severe is CVE-2026-90535?
- High severity. CVSS v3 base score is 7.5 out of 10.